Diamond mining and exploration in Africa
It is estimated that about 60 percent of the world's known diamond reserves are located in Africa, whereas Africa's contribution to the global output was 90 million carats in 2006 or 55 percent. So far Africa had produced diamonds worth some $192 billion or over 76 percent of the world's diamonds by value.
The approximate breakdown of diamond production by value (2007) within Africa is:
* Botswana: $3.2 billion
* Angola: $1.5 billion
* South Africa: $1.6 billion
* Democratic Republic of Congo: $0.8 billion
* Namibia: $0.7 billion
* Other African nations: $0.6 billion (Source: DiamondFacts.org)
Click HERE for an overview (Mbendi)
De Beers halts operations at SA mines (Source: Mining Weekly)
"Diamonds: changing values in Africa" (Source: Mining Journal)
African Producers Weigh Formation of Diamond Cartel"We're on the right side of history, says De Beers Penny" (Mining Weekly)
Angola
Click HERE for an overviewWest African Diamonds/Angola (Kevin Hulsey-Jewelry)
Diamonds were first discovered in Angola circa 1912, and from 1917 to 1975 the Portuguese parastatal, Diamang, had exclusive access to the mining of Angolan diamonds. After independence, Diamang became Empresa Nacional de Diamantes de Angola (Endiama)
"Angola’s diamond hype"
- SMC (Sociedade Miniera de Catoca), which is owned by Endiama (32.8%), Russia's Alrosa (32.8%), Brazil’s Odebrecht Mining (16.4%) and the Diamond Finance CY BV Group (18%) operates the Catoca Mine, the world’s 4th largest kimberlite. Reserves are estimated at 60 million carats. SMC intends increasing production to 5 million carats per year.
- SouthernEra obtained government approval for the opening of Angola's second kimberlite mine, Camafuca, in 2002. The Camafuca Project is located in the Lunda Norte province of northwestern Angola, approximately 20 km southeast of the town of Lucapa. The project area covers the primary kimberlite deposits associated with the Camafuca-Camazamba kimberlite pipe, which is one of the world's largest known undeveloped diamond resources, with a surface area of 160 hectares. The Camafuca Kimberlite pipe is elongate, with its long axis oriented north-south. The pipe is 3,3 kilometres long and averages about 500 metres in width. Results of feasibility studies and exploration activities have shown that the various kimberlite facies of the Camafuca-Camazamba pipe, from surface to a depth of 145 m, contain an estimated total inferred mineral resource of some 209,5 million cubic metres at an average grade of 0,111 carats per cubic metre (cts/m3). This is equivalent to an estimated in-situ diamond content of 23 million carats.
- Development of Angola's third kimberlite mine Camatchia -Camagio was granted to a joint venture with similar shareholders as Sociedade Miniera de Catoca.
- Petra Diamonds, in a joint venture with BHP Billiton, is exploring the Alto Cuilo kimberlites in the northeast of the country. Petra Diamonds Ltd and its Angolan partners, Endiama and Organizacoes Moyoweno, began drilling the diamondiferous kimberlites in 2004.
- BHP Billiton is involved in a second joint venture with a Portuguese bank, Escom; the partners hold three concessions covering 12000km². They are at an earlier stage of exploration.
- Xceldiam Diamond Exploration & Mining's interest in the Luangue Concession are held through the Projecto Luangue Joint Venture in which Xceldiam holds a 40% interest in the alluvial and a 39% interest in the kimberlite licenses. The other participants in the Projecto Luangue JV are the Angolan state's diamond company, Endiama, and a consortium of Angolan nationals, Bapsil Service Lda. In May 2006, Xceldiam entered into a strategic cooperation agreement with Petra Diamonds. In terms of this agreement information is shared and technical, operational and other related activities are co-operated on in the development of Xceldiam’s Project Luangue and Petra’s neighbouring Project Alto Cuilo (where the latter is in JV with BHP Billiton). Petra Diamonds will buy Xceldiam’s Angolan assets in an all-share transaction valued at £32 million, and it has raised a loan of $20m through its partner BHP Billiton to develop Angolan diamond projects, Petra CEO Johan Dippenaar said on March 1, 2007.
- Trans Hex Group has been involved in the mining of the Fucauma (32% share) and Laurica (35% share) alluvial deposits since 2003 and has signed a contract with state diamond miner, Endiama, on the Luana deposit (33% share). The company has also continued kimberlite exploration on its Gango concession where potential for a moderate to low diamond bearing kimberlite has been identified.
- Sociedade de Desenvolvimento Mineiro de Angola, S.A.R.L. (SDM) is a joint venture between Endiama (50%) and Odebrecht (50%) exploiting the Tazua alluvial deposit at its Luzamba project.
- Sociedade Mineira do Lucapa (SML), representing Endiama (51%) and Sociedada Portugese de Empreendimnetos (49%), along with operators ITM Mining, operate several alluvial concessions in the Lundes, viz the Calonda project that produced 199 000 ct, the Mufuto project that yielded 244 000 ct and the Lucapa project 69 000 ct in 2001. SML also holds a 15% interest in Southern Era’s Camafuca project.
- Associacao Chitotolo, owned by Sociedada Miniera de Lumanhe (15%), ITM Mining (50%) and Endiama (35%) mines alluvial deposits and produced 232 000 ct in 2001.
- De Beers involvement in Angola: De Beers first undertook grassroots prospecting in Angola from 1970 to 1975 as the company Condiama, a joint venture with Diamang, the Portuguese parastatal. Operations terminated with the outbreak of civil war in mid-1975. Diamang became Endiama, and De Beers later returned as MATS (Mining and Technical Services) in a joint venture with Endiama, operating from 1979 to 1984 mining the alluvial deposits in the Lunda provinces. Following the conclusion of negotiations with the Angolan Government in 1996, prospecting agreements were entered into for three concession areas being Lunda northeast, Quela (central) and Mavinga in the southeast. From 1996 to 2001 De Beers embarked on an ambitious prospecting programme in partnership with Endiama, to discover and evaluate kimberlites. Due to poor security conditions on the ground at the time, no work was possible in the Quela and Mavinga concessions, but in the Lunda concession some 60 kimberlites were discovered. Most are located under deep sand cover and require further investigation and detailed sampling before some idea of their economic potential is understood. Over this period De Beers spent over U$32 million on the prospecting programme alone. Operations were suspended in May 2001 pending negotiations with the Angolan Government and Endiama on the terms applicable to mining and marketing of diamonds from mines discovered from De Beers prospecting. Following a period of four years in which De Beers could not operate in Angola, in its session of the 27th May 2005, the Angolan Council of Ministers approved the Joint Venture Contract between Endiama and De Beers Angola Prospecting Limited – DEBAP, to exercise the mineral rights for prospecting, evaluation and research of kimberlite deposits in the Lunda North Concession area. The Contract was signed on the 17th of June 2005, and the Joint Venture Company is known as ENDEB. Prospecting operations were scheduled to commence in the third quarter of 2005.
- Gem Diamonds signed a Cooperation Agreement and an option to acquire an interest in the Chiri kimberlite concession in the Lunda Norte province of Angola. A feasibility study will be conducted over Chiri, whereafter Gem Diamonds will have an opportunity to acquire up to 20% of Chiri, a known diamondiferous kimberlite cluster. Chiri is located approximately 5 km from Catoca, one of the world's largest diamond mines and amongst a cluster of other known kimberlites. The Cooperation Agreement concluded with Avantis Angola Inc also provides for a joint venture relationship for the future exploration and exploitation of other Angolan diamond assets.
- Pangea Diamond Fields plc (Also active in Congo -Kinshasa, Central African Republic and South Africa) has been pilot mining the Cassanguidi alluvial project, Lunda Norte Province, north eastern Angola. Diamondiferous gravels are extracred from river terraces and hill-wash deposits using conventional open pit methods and river bed gravels, by pumping from a raft. A total of 25,416 cts was produced by pilot mining from Cassanguidi during the period February 2005 to March 2006. Stone sizes for the open pit operation have varied between 0.23 ct/stone and 0.42 ct/stone, with an average of 0.35 ct/stone. Continuing mining operations were hampered in the fourth quarter of 2006 due to the excessive seasonal rains, resulting in diamond production being significantly less than expected; 5,690 carats were produced during the quarter. Average diamond revenue from sales to Sodiam, Endiama’s marketing arm, have been disappointing and, in the Company’s opinion, well below market value. Plans to develop the project further will be deferred until there is a mechanism in place to ensure sales at market-related levels can be achieved and are sustainable. Discussions regarding the sale and marketing procedures are ongoing.
- Nare Diamonds Ltd (Lonrho Mining Ltd) has signed a joint venture agreement with state-owned Endiama to develop the 3,000 sq km Lulo diamond concession in Angola. The Lulo concession is located in the Cuango River catchment area within the Lunda Norte Province of northeastern Angola.
- International Gold Exploration AB has been granted a concession right in the Luanda Norte province, one of Angola's richest diamond regions, and one in the Kwanza Sul province. The Kwanza Sul province hosts the third most important diamond primary source in Angola. Luxinge and Nhefo in Lunda Norte and Cariango in Kwanza Sul are both primary and secondary diamond exploration projects.
Based on the results from the bulk-sampling program underway, the concessions are expected to produce 120,000 carats per year once IGE enters into its 5-year full production program in 2009. The Angolan government authorised the concession of rights of diamond prospecting of the Lacage kimberlite, Luacheze district, eastern Moxico province, to the National Diamond Company of Angola (ENDIAMA), in an area of 3,000 square kilometres. In the same document the government authorised and approved the setting up of the Association in Participation in Lacage, between ENDIAMA, International Gold Exploration (IGE), the "Sociedade Mineira do Leste" (Somileste) and Magma - Commerce, Industry and Supply of Services.
Participation quotas of the referred contract are 51 percent for ENDIAMA, 43 for IGE, four for Somileste and two for Magma.
- Signet Mining Services Ltd secured a concession to mine diamonds in Angola. The pipe Chirri is situated near the town of Saurimo and approximately 5km from the Catoca kimberlite mine. Catoca and Matikara have conducted historical work at the site, including bulk sampling and delineation drilling. Although the drilling programme was small, the pipe was confirmed to be to be over 600m in width and estimated to be as large as 50 ha.
Botswana
Click HERE for an overview
Diamond Mines of the World/Botswana (Kevin Hulsey-Jewelry)
Click HERE for a map showing the location of diamond mines in Botswana
Botswana still world's greatest source of new diamonds (Source: Mineweb)
History
In early 1967, after a 12 year search, a team of De Beers geologists found abundant quantities of ilmenite and garnet - two of the chief indicators of diamondiferous kimberlite - near the village of Letlhakane in north-central Botswana. After further exploration, the pipe at Orapa was found later that year.
Source: De Beers
- Debswana Diamond Company (De Beers 50%, Government 50%) is by far the world's largest diamond producer by value. Debswana's diamond mining operations are situated at Jwaneng, Orapa, Letlhakane and Damtshaa. Jwaneng is the richest diamond mine in the world and is situated 170 kilometers west of the capital Gaborone. Orapa, Letlhakane and the youngest Damtshaa mines are located roughly 240 kilometers west of Francistown. The Orapa pipe is the world's second largest diamond-producing kimberlite pipe. In 2005, Debswana Mines produced a total of 31,9 million carats;
- MTP.V;MTP-WT.V35 prospecting licenses, 100% ownership over 28 PL's (1,77 million hectares), 60% over 7 PL's (0,48 million hectares) in joint venture with AfriOre Botswana (Pty) Ltd.Motapa has entered into a joint venture agreement with Stornoway Diamond Corporation, under terms in which Stornoway has a right to earn a 50% participating interest in a portion of Motapa's Botswana land package by meeting certain vesting requirements, including the funding of US$2m in exploration expenditures and the transferring to Motapa of US$1m in Stornoway shares.
- Firestone Diamonds plc (FRDIF.PK),mines alluvial deposits in South Africa) has been awarded a prospecting right on the BK11 kimberlite with indicated grades of between two and 17 carats per hundred tonnes. It is in the Orapa area with a new mine being developed five kilometres away at AK6. The company also has joint ventures and is involved in early stage exploration in the Mopipi area, 50 km to the west of Orapa mine. In 2007 the company announced that it had discovered 4 new kimberlites at the Tsabong area project, 280 km southwest of Jwaneng. Firestone subsequently reported that the estimated size of the BK11 kimberlite had increased from 6,5 ha to 8 ha. The company announced in December, 2008, that it had discovered 13 kimberlites to date at the Tsabong project in Botswana. The number of kimberlites in all license areas had reached 92, 23 of which are diamondiferous.
- DiamonEx Ltd (Australian, ASX:DON: BSE:DIAMONEX) is developing the Lerala diamond resource; comprising five diamondiferous kimberlite pipes which were originally discovered in the late 1980's by De Beers. The estimated Indicated Diamond Resource to a depth of 110m from surface, is 13.5 million tonnes at a grade of 27,41 carats per hundred tonnes. This represents approximately 3,7 million carats of diamonds.
- SouthernEra Diamonds Inc. announced on 28 March, 2007, that it had acquired a 55% interest in the BK16 kimberlite pipe located within the Orapa Kimberlite Field. Under the agreement, SouthernEra has the right to earn up to a 70% interest in the project by funding exploration to the completion of a definitive feasibility study. BK16 is located 40 kilometers to the east and 12 kilometers to the north of De Beers' Orapa and Letlhakane diamond mines, respectively. SouthernEra has entered into an agreement with Kenrod Engineering Services (Proprietary) Limited, a Botswana registered company which owns the BK16 prospecting license.
- Tawana Resources NL (Australian, TWNAF.PK) has been awarded a prospecting licence over eight kimberlites in the Orapa district of Botswana. The Orapa kimberlite field is one of the largest diamondiferous kimberlite fields in the world, containing 79 known kimberlites, of which the majority has been proven to be diamondiferous.
- Pan African Mining Corporation announced in May 2007 that the Botswana Geological Survey had granted six Prospecting Licences to its local, wholly-owned operating subsidiary PAM Botswana (Pty) Ltd. These three-year licences, form two separate diamond exploration target blocks, with a combined area of 5476 km2, located in the Ngamiland area of northwest Botswana. Selection of the prospects was based upon screening of remote sensing and aeromagnetic data as well as geochemical data. The newly licensed blocks contain a cluster of bulls-eye circular features aligned along a lineament. These features possess characteristics closely comparable to those associated with known sub-Kalahari kimberlites. One of these circular targets has an outer diameter in excess of 600 metres. The company reported in January, 2008, that it had completed the first phase of geochemical sampling on its Fairy Ring and Okavango Projects in the Northwest of Botswana. Each comprises three Prospecting Licences aggregating approximately 3000 sq. km, for a total area of some 6000 km2. The company's Okavango licenses are adjacent to claims recently acquired by De Beers in Botswana, and that company's Namibian affiliate (Namdeb) in neighbouring Namibia. This activity has been stimulated in part by an increasing consensus that the Congo craton, which hosts important economic diamond deposits, extends into northwest Botswana. Furthermore, this area is strategically located close to two major surface concentrations of diamonds and G10 garnets in the vicinity of Omatako and Tsumkwe, to the west in Namibia. It could therefore host the primary kimberlite sources of these two important unexplained kimberlite pathfinder anomalies.
- Petra Diamonds Ltd announced in May, 2007, that it had found a new kimberlite within its license areas and identified 20 new "highly encouraging" targets in its Orapa North licence block in Botswana. The company also said it had acquired two new prospecting licences in the Jwaneng area which hold two known diamondiferous kimberlites.
- Gem Diamonds Ltd [LSE:GEMD] announced on May 29, 2007, that it had bought Gope Exploration Company (GEC) from De Beers and a subsidiary of Xstrata for a cash consideration of $34-million, or R241-million. GEC was a De Beers Prospecting and Falconbridge Exploration Botswana joint venture, which focused on exploring a known kimberlite pipe in central Botswana. It has an indicated resource of 79 million tonnes down to 400 m below surface at a grade of 19 carats per hundred tonnes. A parcel of 3 400 carats recovered during sampling by De Beers was valued at $121/ct.
Click HERE for an overview
The government keeps statistics concerning diamond production and trading through the Bureau d’Évaluationet de Contrôle de Diamant et d’Or (BECDOR). BECDOR was established in 1982 to oversee the internal diamond market and to valuate official exports. It also maintains a database concerning all diamond production in the country. It estimates that there are approximately 50,000 licensed diamond diggers, or creuseurs, in the CAR.
- Vaaldiam Resources Ltd (Canadian) has been involved in early stage exploration.
- United Reef Ltd (Canadian) investigated an alluvial diamond project. The diamond project advanced through several stages of exploration and small-scale production and was closed in early 1998.
- DiamondWorks Ltdtook 100% control of Central African Mining Company SARL for CDN $53m, payable by shares. Most of the country's annual output of >600,000 carats of high-quality diamonds via legitimate channels is from artisan workings for alluvial placer diamonds in the company's 6 concessions totalling 11,577km².
- Gem Diamonds, through Gem Diamond Centrafrique, currently holds a 25-year mining permit and a three-year research permit for the Mambéré River project which covers an 80 km stretch with a strip approximately 5 km wide on either bank of the Mambéré River near the town of Berberati. Current exploration focus is on the area known as "le Buckle". Diamondiferous gravels have been identified by previous explorers throughout the area. Development of the project is through a joint venture owned 75 % by Gem Diamond Centrafrique and 25 % by the Government of the CAR.
- Pangea Diamond Fields plc is exploring the Dimbi Project concession area, situated in southern CAR along the DRC border between the Oubangui River in the south and the Kotto River in the north, and has commenced a bulk sampling exercise. The alluvial diamond deposits of the Dimbi area are associated with a palaeo-channel system of the Kotto River, which originally flowed southward past Dimbi. BRGM monitored pits in the Akongo River close to the bulk sample plant site reported grades of between 0,25 and 3,56 ct per cubic metre. In May, 2007, the company acquired a second project; the Etoile project covers an area of 3,872 square kilometres and is located some 300 kilometres northeast of the Dimbi project, but within CAR's Mouka Quadda diamond province.
- Energem Resources Inc (Canadian, ENM.TO) is exploring the Bangana (743,6 km²), Bria (74,.7 km²), Kotto (962,5 km²) and Ouadda (1683.0 km²) concession areas.
Congo (Kinshasa)
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West African Diamonds/République démocratique du Congo (Kevin Hulsey-Jewelry)
The Congo (DRC) is presumed to be Africa's largest diamond producer, but production figures are not available. Most of the DRC's production is produced by the informal sector. In mid-2004 the Kimberley Process struck the country off its list of certifiable diamond producers accusing it of dealing in blood diamonds which resulted in the DRC ceasing exports of diamonds. It is estimated that roughly a third of the DRC's production is smuggled out of the country every year.
- Artisianal mining of placer diamond deposits in the DRC takes place along the Bushimaïe and Lubilash tributaries to the Sankuru River near the town of Mbuji-Maye (formerly Bakwanga) in the Kasaï-Oriental province of souther-central DRC, and along the Tshikapa River in the Kasaï-Occidental province.
- Société Minière de Bakwanga (MIBA), which is a joint venture between Belgian company Sibeka (20%) and the DRC government (80%), owns the only functioning mine in the country, Mbuji Mayi. The shareholders of Sibeka were Umicore, 80% and De Beers, 20%. In May 2006 Mwana Africa plc acquired Umicore’s subsidiary, Sibeka. Over the past five years MIBA has produced an average of 6 million carats of diamonds per year. It has mining and exploration titles covering an area in excess of 45,000 km2 where it is discussing joint ventures with major diamond producers.
- De Beers signed a confdentiality report with Oryx Natural Resources as part of a due diligence exercise for the possible development of the Sengamines diamond concession in 2004.
- BRC Diamond Corporation (Canadian and in which gold junior Banro holds a 27,5% stake) controls 5,426 square kilometres and retains a further 11,100 square kilometres through option agreements on ground that historically has been the largest diamond producing region of the DRC. The geology of the region represents an extension of the Angola Craton, which underlies the diamond fields of Lunda Norte Province, in northeast Angola. The company is involved in early stage exploration of both the kimberlite and alluvial potential of the area. By the end of 2007, BRC proposed merging and acquiring all of the outstanding shares of Diamond Core , the South African diamond exploration company, in exchange for BRC shares. BRC had been awarded a further 58 diamond exploration permits in the Democratic Republic of Congo, the firm said in December, 2007. The Toronto-based company now holds directly, or controls through option agreements, a total of 116 exploration permits, covering an area of 38 140,5 km² in the provinces of East and West Kasai and Bandudu in the south, Equateur and Oriental in the north, and Maniema in the central-east of the DRC.
- SouthernEra has secured 56 exclusive diamond exploration permits covering more than 16,000 square km in the diamond-rich Kasaï Provinces. This area is producing up to 20 million carats of diamonds per year. In a joint venture formed in October 2005 with BHP Billiton on 39 of SouthernEra’s 56 permits, exploration has commenced for primary diamond deposits. In May 2006, SouthernEra signed an agreement with Nyumba Ya Akiba SPRL, a local Congolese company, acquiring an immediate 74% undivided interest in eight exploration permits covering 2,744 km2 of diamond prospective ground in the Kabinda area of the Kasai Oriental Province. SouthernEra has also secured alluvial diamond permits within the Tshikapa / Kasai / Luebo alluvial diamond field in the Kasaï-Occidental Province, and also within a second major alluvial diamond field in the Kasaï-Oriental Province. SouthernEra controls a 34 kilometre stretch of Kasai River and 2 kilometres of the Tshikapa River within this diamond producing area of southwestern DRC. SouthernEra owns a 100% interest in four permits covering 80,35 km2 and a 70 percent interest in a further four permits covering 77,73 km2.
- BHP Billiton is involved in a joint venture with Gravity Diamonds and early stage exploration.
- Gem Diamonds holds various concessions in the Mbelenge, Lubembe, Longatshimo and Tshikapa areas in the Kasai Occidental Province, and the Mbelenge area to the north of this. The Mbelenge project comprises four concessions, each with mining permits, along the Kasai River from the port of Djoku Punda, south for approximately 20km. The Lubembe project comprises 22 concessions on the Tshiumbe and Lubembe Rivers. The area was previously prospected in some detail with small alluvial mines established. Lubembe is considered to have significant kimberlite potential with 17 targets identified in a limited survey in 2005. The Longatshimo project comprises 12 concessions on or around the Longatshimo River, with a combination of mining and reconnaissance permits. The Tshikapa project hosts two concessions on the bank of the Tshikapa River each with mining permits.
- African Diamonds plc (AFCDF.PK, also active in Botswana, Guinea, Sierra Leone), the AIM and Botswana-listed diamond explorer, has acquired a 35,42 percent share in Bugeco S.A., a private Belgian company and with it, the right to appoint a director. The total consideration paid was $1,616,420 in cash. The key asset of Bugeco is a joint venture with De Beers on 21 licences in the Democratic Republic of the Congo (DRC), covering 807 000 hectares of prospective diamondiferous ground. Initial exploration has discovered several new kimberlites, in an area where alluvial diamonds are already in evidence. Analysis indicates the presence of microdiamonds in several of the newly discovered kimberlites, n what appears to be two new kimberlite clusters. Reconnaissance magnetic and detailed airborne magnetic (DAF) geophysical surveys have been completed over the entire licence area and ground magnetic, gravity and electromagnetic surveys over specific anomalies have resulted in the identification of new drill targets. Extensive ground sampling using helicopter and vehicle access is ongoing. The 2007 work programme will focus on further discovery drilling and delineation. This work will prioritise bulk sampling.
- Pangea Diamond Fields plc is exploring the the Yusufu and Ikulu alluvial projects on the Longatshimo River, and intends bulk sampling the properties. A plant site has been identified and an operational team is in the process of being assembled. The required plant has been designed and is currently being manufactured, with operations expected to commence mid 2007. It was reported in January, 2008, that a bulk sampling plant had arrived at Pangea Diamondfield's Longatshimo River project and plant construction was in progress.
- Mwana Afica plc bought Australian firm, Gravity Diamonds, which has been exploring rights held by BHP Billiton in the Kasai Crater region, in November 2006, for $34m , and announced on March 16, 2007, a C$69.7 m share offer for SouthernEra which has adjacent properties.
- Rockwell Ventures Inc (Canadian, RVINF.OB, RVI.V) has rights over 60 km along the Cuango River where artisanal mining is taking place.
- Lindian Resources Ltd is exploring the Tshikapa diamond field, in the West Kasai region of the DRC. The area is about 600 km east-southeast of Kinshasa, the capital of DRC. The Tshikapa Diamond Project consists of four licence areas covering about 800 sq km.
Côte d'Ivoire
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Cote dIvoire has historically produced approximately 165 000 carats per year. All of the alluvial mining is sourced from the fields located at Tortiya and Seguela which is located 100 km from Korhogo. Although kimberlites have been identified in these areas, none have been mined or evaluated.
- Golden Star Resources acquired the Tortiya diamond and gold property in 1996 based on an extensive history of alluvial diamond production. No exploration had ever been directed to the discovery of the source of these alluvial diamonds, nor the alluvial gold reportedly associated with them. Based on the regional geology and structural setting, the company believes the property has potential for the discovery of diamondiferous kimberlites and shear hosted gold mineralization. Tortiya is located in central Côte d’Ivoire in an area of potential civil disturbance and is currently (2007) under a state of force majeure.
Click HERE for an overview
Gabon
Click HERE for an overview- Alluvial diamonds have been recovered from Makongonio, in the south near the border with Congo and in the Mitzic region.
- De Beers commenced diamond exploration in Gabon in 1998. The country hosts a potentially prospective area of 190 000 km². De Beers currently holds some 33 000 km² in three prospecting permits in the central-northern and southern parts of the country. Reconnaissance and follow-up sampling was completed over all of the company’s ground holdings (over 66 000 km²). Four airborne magnetic surveys have been flown to date (two in 2000 and two in 2002) covering a total area of approximately 18,000km². A total of forty-seven new kimberlites and related bodies were discovered by De Beers during the 8 years of operation within Gabon. Currently, no active exploration is taking place, but De Beers still maintains a presence in the country.
- SouthernEra actively explored for diamond deposits in Gabon from 1999 to 2004 and discovered eight possible kimberlitic bodies sub-cropping in various small streams that were positive for kimberlitic indicators. In addition to the discoveries at the Makongonio Project, two ultramafic dykes were discovered in July in trenches within the Kango diamond permit, in northwestern Gabon.
- Motapa Diamonds Inc holds 2 exploration permits encompassing 3.3 million hectares. Reconnaissance stream sediment sampling over 75% of the license area had yielded abundant chromite and ilmenite grains indicating the presence of kimberlite in certain areas of the Lebiri license.
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Ghanaian gem exports have risen in recent years from 626,000 carats in 2000 to about one million in 2005, a rise that has been driven, local authorities say, by higher diamonds prices. About 80% of Ghana's diamond production comes from small scale miners. With little data available on their output, it is difficult to compare domestic production with export data. About 490 local buyers have been registered and local miners - believed to number as many as 10,000 - are currently being registered.
- Ghana Consolidated Diamonds Ltd’s Akwatia diamond mine is located about half way between Accra and Kumasi and is the only formal operating diamond mine in Ghana.
- The majority of diamonds is recovered by artisanal miners from alluvial and raised terrace gravel workings in the Birim Valley.
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- AREDOR, a joint diamond-mining venture between the Guinean Government (50%) and an Australian, British, and Swiss consortium, began production in 1984 and mined diamonds that are 90% gem quality. Production stopped from 1993 until 1996, when First City Mining of Canada purchased the international portion of the consortium.
- De Beers systematically prospected for kimberlites within Guinea between November 1995 and February 2004. During this period, geophysical surveys were conducted along with the collection of reconnaissance and follow-up samples. From these activities De Beers were successful in the discovery of 25 new kimberlite occurrences. Between beginning of 2004 and May 2006, no active exploration was taking place, but De Beers still maintained a presence in the country. In 2006, the Guinean subsidiary company Debsam Guinea was awarded three exploration licences in the eastern part of the country. Currently a team of geophysicists is on site conducting preliminary assessments.
- Trivalence Mining Corporation (Canadian, TMI.V, also active in Botswana) has restarted its diamond production at the Aredor alluvial mine. Two of the company's Manitowoc draglines are operating at BAX Block, based on the sampling data from Bridge Oil the BAX Block is estimated to contain an indicated resource of approximately 1,8 million tons of gravel to yield a projected 100,000 carats.
- AFDM.PK, AFD.L) and its wholly owned subsidiary Grampian Resources Limited, holds the rights to three Exclusive Exploration Licences, Seria and Bomboko, located on the River systems of Bomboko and Bonbokoni, and Fangamadou, located on the flood plains of the River Meli.
- West African Diamonds, the AIM-listed diamond exploration firm, has won the right to explore the six hectare Droujba kimberlite pipe in Guinea.
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A large proportion of the country is underlain by the southern portion of the Archean Kaapvaal craton, host to kimberlites and economic diamond deposits in southern Africa. More than 200 kimberlite occurrences are known in Lesotho, primarily dykes but including approximately 33 volcanic pipes of which 24 are reportedly diamondiferous. They are Cretaceous in age and intrude flat-lying Triassic sedimentary rocks and a thick sequence of Jurassic flood basalt.
The country has a long history of diamond production, mainly from alluvial deposits. De Beers mined the Letseng la Terae kimberlite between 1976 and 1982 and produced in the order of 280,000 carats. The Letseng la Terae kimberlite was recently put back into production and has the distinction of producing some of the highest dollar value per carat diamonds in the world. Diamond grades at Letseng la Terae are very low, between 2 and 2,5 carats per one hundred tonnes of kimberlite, but diamond value is reported to be over US$1,000 per carat. This high average diamond value is a result of consistent but infrequent recovery of very large, exceptional quality diamonds.
Other Lesotho kimberlites of economic interest and in varying stages of development / evaluation include the Liqhobong, Kao and Kolo occurrences.
Lesotho Kimberlite Locality Map
- Gem Diamonds Ltd [LSE:GEMD] is operating the Letšeng mine. It has been producing 50,000 carats a year, but, with fresh investment under its new owners, it plans to double that to about 100,000 carats a year.
Letšeng Diamonds Limited is owned 70% by Gem Diamonds and 30% by the Government of the Kingdom of Lesotho. Operated by De Beers between 1977 and 1982, Letšeng was reopened in 2004 and acquired by Gem Diamonds in 2006. Letšeng Mine consists of two primary vertical kimberlite pipes, together with deposits of alluvial gravels. The two pipes are adjacent with cone-shaped sections and confirmed vertical depths of 495 m and 655 m, respectively. Recent average grade across the two pipes is 2,06 cpht. Letšeng currently has a processing capacity of approximately 2,6 million tonnes per annum, but a recent decision to invest US$45 million in its processing capacity will see this double to 5,2 million tpa by end 2008. Letšeng has produced two of the world's largest diamonds - the 601 cts Lesotho Brown in the mid 1960's and the 603 cts Lesotho Promise recovered in September 2006 (the 15th largest diamond ever recovered). The Lesotho Promise was sold for US$12,4 million.
The Lesotho Promise diamond weighing 603 carats which was sold for $12,4m.
Source: Gem Diamonds
The UN Security Council in December 2006 renewed for six months an embargo, initially imposed in 2001, on the trading of rough diamonds from Liberia, but the ban was lifted on 27 April 2007.Source: Gem Diamonds
- is exploring the Mothae kimberlite where previous sampling undertaken in 1966 by Lonrho Ltd , yielded a grade of approximately 2,8 carats per hundred tonnes.
- European Diamonds plc [AIM:EPD] has a near-surface resource at its Liqhobong project in Lesotho of 13,4 million tonnes at 0,283 carats per tonne with a gross value of $265m at an estimated $70/carat. The company is currently (2007) producing around 20,000 carats/month from the mine, with plans for an expansion. The independently verified resource at the main pipe kimberlite has been measured to 45 metres below surface. The main kimberlite pipe is known to extend to 650 metres below surface.
- Thabex Exploration [JSE: TBX], through 80%-owned, Angel Diamonds Pty) Ltd, is exploring the Kolo kimberlite pipe, 38 km south-west of Maseru in the Mafeteng district.
- Lesotho Diamond Corporation plc (Registered in Gibraltar) has the rights to the Kao kimberlite pipe in Lesotho's Buthe Buthe district and was attempting to raise money to develop a mine. River Diamonds plc (RVD.L) announced in April 2007 that they have entered into an agreement to purchase a 4,8% working interest in Lesotho Diamond Corporation plc for £4 million with an option to acquire a further 2,3% by 20th April 2008 for £2,121,212. The Kao pipe has a proven and probable reserve of 147 million t at a grade of 6,9 carats per hundred tonnes. SRK Consulting has calculated the Net Present Value of Kao to be £129m, assuming a base case of US$240/carat. In May 2007 Pangea Diamond Fields had a conditional cash and shares offer accepted to buy at least 40% of Lesotho Diamond Corporation (LDC). According to Pangea's statement, key shareholders in LDC approached Pangea to make a rival offer after an agreement was struck to sell shares in LDC to River Diamonds.
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West African Diamonds/Liberia (Kevin Hulsey-Jewelry)
- Artisanal mining of the alluvial terrace gravels located along the Lofa River, Mano River and Morro River, in the Lofa province of northeastern Liberia, and in the Gbapa area on the Guinea boarder.
- Diamond Fields International Ltd through its subsidiary company Diamond Fields (Liberia) Inc. ("DFL") has been actively exploring both the Grand Cape and Grand Geddeh exploration permits, which are held under a joint venture agreement with Ducor, a Liberian registered company. Regional exploration of the two properties has defined 10 diamond anomalies associated with G10 garnets in the Grand Cape property, and seven gold anomalies, six of these anomalies being located with the Grand Geddeh property. The Company has now changed its exploration strategy from regional assessment to specific evaluation of these exploration targets. The current focus of activity has been on a gold anomaly within the Henry Town region of the Grand Cape property, where native gold is exploited by local artisans, which previously returned gold values of up to 13g/t gold in DFL's grab samples. The gold is contained in quartz veins associated with a Birrimian (Proterozoic) age transgressive left lateral shear zone, which boudinages and juxtaposes basement gneisses and supracrustal lithologies.
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Mali
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Mauritania
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Mozambique
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Namibia
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Diamond Mines of the World/Nambia (Kevin Hulsey-Jewelry)
History
The find that constituted the discovery of diamonds in the Namib Desert was made in April 1908 at a railway siding near Lüderitz. Zacharias Lewala, one of the men employed to keep the railway track free of drift sand and who had previously worked on the Kimberley diamond fields, picked up a stone and recognised it as a diamond. This discovery led to the August 1908 proclamation of the Sperrgebiet, or forbidden territory, a region that today stretches some 360 kilometres along the coast and reaches 100 kilometres inland. According to the terms of the proclamation, nine companies obtained rights to prospect and mine in the Sperrgebiet. After the outbreak of World War One, South Africa invaded the German protectorate of South West Africa (SWA, now Namibia) and assumed administration of the country. Five years later, Sir Ernest Oppenheimer, acting on behalf of Anglo American Corporation, acquired control of the nine mining companies and in February 1920, amalgamated them into the Consolidated Diamond Mines of South West Africa (CDM). In 1923, the SWA Administration and CDM concluded the Halbscheid Agreement, which accorded CDM mining rights in the Sperrgebiet. Through negotiation, CDM's rights in the restricted area were extended to 31 December 2010. In 1931, De Beers Consolidated Mines bought Anglo American's interest in CDM, later making CDM a wholly owned subsidiary in 1975. In spite of previous exploration attempts, diamonds were only discovered on the north bank of the Orange River in 1928. This led to the establishment of Oranjemund in 1936 and the eventual transfer of the company's headquarters from Lüderitz to Oranjemund in 1943. Based in Switzerland, De Beers Centenary AG was formed in 1990 to head a group of companies that incorporated the international interests previously held by De Beers Consolidated Mines Limited. CDM was one of those companies. In 1994, in terms of an accord concluded with the Namibian government, CDM was reconstituted as Namdeb Diamond Corporation (Pty) Limited, an equal partnership between the government and De Beers Centenary AG.
Diamonds were first discovered on the south bank of the lower Orange River by Dr Ernst Reuning in 1957. Following this discovery, prospecting on the Northern Bank started in 1968. Exploration and sampling for Auchas deposit started in 1986. Auchas mine started production in June 1990 and closed in June 2000. Daberas mine started in October 1999 and it was officially inaugurated on the 30 May 2002. As of 2006, Daberas has a 4 years life of mine left. A pre-feasibility study for the Sendelingsdrif area which was completed in 2004 indicated a potential seven year life of mine. A full feasibility study will be undertaken during the first quarter of 2008. (Source: De Beers)
"Celebrating a Century of Pretty Stones" (Source: New Era)
GeologyThree major, long-standing transport pathways - which can be likened to conveyor belt systems - have been instrumental in moving diamondiferous sediment from source localities to sink areas: Fluvial conveyor - principally the Orange-Vaal River drainage system, marine conveyor - in this passive margin setting, the Atlantic wave regime is vigorous with a strong north-bound longshore drift driven by a prevailing southerly wind regime, desert conveyor - the arid climate and prevailing southerly wind regime of the Namib Desert facilitates onshore movement of marine-derived sediment back into a land-based sink. En route, and over geological time, diamonds have been concentrated in a number of different placer types that span terrestrial and marine settings. Following the discovery of diamonds to the north of the Orange River mouth in 1928, an ore body was delineated, which is today known as Mining Area 1. The area consists of raised beaches over a distance of approximately 100km north of Oranjemund, to Chameis Bay along the present day coastline. Bordered in the east by a geological boundary known as the "east cliff", this strip of land is nearly 3km wide in the south, narrowing to about 200m in the north. A typical beach consists of a layer of gravel between ancient high and low water marks, a storm beach or ridge and a marine platform or shelf containing gravel. Diamonds may be found in any portion, but occur most abundantly in the beach and shelf gravel found upon and within the deeply gullied and highly contorted bedrock. Ore deposits are about 2m thick, while the overburden thickness can reach a thickness of 20m in places. (Source: De Beers)
- Namdeb Diamond Corporation (Pty)(De Beers 50%, Government 50%) is currently producing less diamonds from onshore operations than that being produced by De Beers Marine Namibia (De Beers 70%, Nambeb 30%), which produced a total of 922 000 carats in 2005. Since 1908 more than 100 million carats have been produced from the dwindling and, in many instances, depleted reserves (see video)
- Diamond Fields International Ltd (Canadian), through its subsidiary Diamond Fields Namibia, owns a 100% interest in a mining license offshore (71,600 hectares). It has recovered more than 110,000 carats to date.
- Trans Hex has three shallow marine licenses in the Cape Fria area, four in the Toscanini (both north of Walvis Bay) and two south of Hollandsbird Island (north of Luderitz Bay). The company also has a resource of 30 million cubic metres of diamondiferous gravel at the Northbank project located in block 9, on the Orange River.
- Afri-Can Marine Minerals Corporation (Canadian) is exploring an offshore block covering an area of 994 sq. km, 105 km. north of Luderitz.
- Rusina Mining NL (Australian) investigated and abandoned the onshore area from Cape Fria northwards to the Angola border.
- Reefton Mining NL (Magna Mining) is exploring a 220 km onshore stretch from Möwe Bay to Cape Fria.
- Mount Burgess Mining NL has been exploring the Tsumkwe project, which is located 450 km northeast of Windhoek on the Botswana border and covers some 8,000 square kilometres held under 9 Exclusive Prospecting Licences seven of which are in joint venture with Kimberlite Resources (Pty) Ltd. Motivation for the project includes that it is located on the southern margin of the Congo-Angolan Craton, just south of Limpopo-Botswana dyke swarm, at a distance similar to the Orapa-Letlhakane kimberlite province in neighbouring Botswana, over a long-lived, stable basement high with Pre-Damaran basement dated >2,000 my, just south of the Sikereti kimberlites and south west of the Nxau-Nxau kimberlite field in Botswana; and in an area where 8 macrodiamonds, together with significant numbers of G9 and G10 garnets have been discovered, delineating discrete anomalies which the company believes have been sourced locally.
- 's Kavango Project (24 Exclusive Prospecting Licenses encompassing 2,09 million hectares) in northeast Namibia, using high resolution magnetics, has resulted in the discovery of eight kimberlites. With the exception of two (which have less than 10 m of cover), the kimberlites are covered by approximately 50 m of overburden sediments of the Kalahari formation. Gravity profiles over the confirmed kimberlites suggest that these bodies range from 300 to 500 m in diameter.
- Bonaparte Diamond Mines NL Namib Project:
The Namib project is located offshore in the vicinity of Hollamsbird Island, some 250km north of the port of Luderitz on the coast of the Republic of Namibia. Active marine diamond mining operations occur off Luderitz and extend some 100 km further north of Hottentot Bay. The Namib Project comprises Exclusive Prospecting Licence (EPL) EPL3241 (Tsauchab Licence), and EPL3323 (Meob Licence) which are not contiguous but lie in close proximity. More recently the project area has been expanded by the inclusion of an EPL application, EPL 3533 (Tsauchab East Licence) which lies adjacent and inshore of the Tsauchab Licence. These tenements are held in Joint Venture with a Namibian Company, Tungeni Investments cc and represent “grassroots” projects off the Namibian coast.
The Tsauchab and Tsauchab East leases lie within the submerged trajectory of the Tsauchab River palaeo channel and also within a south facing coastal embayment. Studies have shown that such features present favourable environments for diamond entrapment and improvement of diamond distribution. On a regional basis, there is evidence of alluvial diamond occurrence along the coastline east of the Meob and Tsauchab leases and reconnaissance seabed sampling over nearby leases by other explorers has identified marine diamond occurrences both to the north and south of the Tsauchab Lease.In the vicinity of the Tsauchab Lease, 5.09 carats have been recovered to the north of the area in 2002 and 15.69 carats have been recovered to the south of the area in 2003 where the largest stone recovered was 0.49carats.
Luderitz Project:
The Luderitz Project incorporates two Joint Operations Agreements (JOA) between Bonaparte's 100% owned Namibian subsidiary, Bonaparte Diamond Mines (Namibia) (Pty) Ltd (BDN) and Diamond Fields (Namibia) (Pty) Ltd (DFN), a 100% owned subsidiary of Diamond Fields International Ltd. The EPL1607b JOA gives Bonaparte exclusive rights to use the Bonaparte Seabed Sampler (BoSS) to explore for diamonds in Exclusive Prospecting Licence area EPL1607b for an initial period of 3 years in return for 50% interest in mining of resources identified by Bonaparte. The project area covers approximately 140 km2 and is located 55 km north northeast of Luderitz, in close proximity of mining licence areas held by Namibia's three leading marine diamond producers, Namdeb, Samicor and Diamond Fields. Previous exploration work conducted in the tenement by Diamond Fields during the late 1990's includes a complete geophysical survey from which a number of prospective targets have been identified as well as a limited amount of seabed sampling which confirmed the presence of diamonds in the property.
The ML111 JOA allows Bonaparte to use the BoSS to carry out a program of resource development sampling in DFN's Mining Licence area ML111 in terms of this agreement. Bonaparte will have exclusive access for 6 months to two designated resource development areas (Diaz Prospect 1 and Diaz Prospect 2) covering a total area of approximately 1,600,000m2 in ML111. Bonaparte will carry out seabed sampling to define areas of Indicated Resource (in compliance with JORC guidelines) in which Bonaparte will then retain a 30% interest in any subsequent mining thereof by DFN.
Bogenfels Project:
The Bogenfels project lies approximately 100km north of the Orange River and comprises an area covering approximately 2,700 km2 off the coast of southern Namibia situated adjacent to the current producing marine mining licence areas held by Namdeb (De Beers/Namibian Government partnership). It comprises three licences; EPL3407, EPL3403 and EPL3404. The agreements are subject to approval by the Minister of Mines and Energy, Namibia. The Exclusive Prospecting Licence for EPL3407 (Mirror Mountain) was granted in November 2005 and applications for EPL's 3403 and 3404 are pending approval by the Namibian authorities. The project is held in Joint Venture with two Namibian companies, BV Investments cc and Mirror Mountain Mining cc for exploration and development of highly prospective marine diamonds, where Bonaparte retains an 80% interest.
Boegoe Hills Project:
The Boegoe Hills project comprises EPL3104 and covers an area of approximately 280 km2 which lies adjacent to the onshore mining licence area held by Namdeb, approximately 100km north of the mining settlement town of Oranjemund. The area is considered prospective for alluvial diamonds and lies approx 18 km to the east of Chamais Bay, where commercial diamond production has been carried periodically since the mid 1960's. The project is a JV between Bonaparte and Nassed Enterprises (Pty) Ltd, a Namibian Company, where Bonaparte can earn an interest of 75%. A geomorphological assessment of the data and a geological model for the evolution of the area shows several possible ancient river channel deposits (palaeochannels) as well as a possible ancient shoreline. These features present prospective targets for follow-up.
- Dahava Resources announced in January, 2008, that it had started limited production activities at its Lower Orange river property in Namibia. The company has obtained the right to prospect and mine on Block 4 of EPL 2610. Previous prospecting of the gravels indicated a grade of 1.3 to 1.78 carats per hundred tonnes
Sierra Leone
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West African Diamonds Mines - Sierra Leone (Kevin Hulsey-Jewelry)
Sierra Leone exported 603 623 ct of diamonds in 2007, in line with the previous year, but the value of sales rose to $142-million as quality improved, a government official said in January, 2008. The value of exports had increased from $127-million in 2006, when 603 868 ct were exported.
History
Sierra Leone is renowned for the quality of its diamonds and for the recovery of some of the most spectacularly large stones of very high value. The largest diamond, discovered in February 1972, was the 969,8 ct 'Star of Sierra Leone'. More recently, in 1996, two stones weighing 188 ct and 283 ct were recovered and sold. Annual output reached a peak of around 2 million ct in the late 1960's, with output declining thereafter. By 1997, output was seriously disrupted by RUF rebel activity, with most of the diamondiferous areas becoming off-limits.
Sierra Leone's established diamond fields cover an area of almost 20,000 km2 (over one- quarter of the country) in the southeastern and eastern parts of Sierra Leone. They are concentrated in Kono, Kenema and Bo Districts and are mainly situated in the drainage areas of the Sewa, Bafi, Woa, Mano and Moa Rivers. Kimberlites, the primary source of diamonds, were first discovered in 1948 in the Koidu area and subsequently at Tongo. Alluvial diamond concentrations occur in river-channel gravels, flood-plain gravels, terrace gravels and in gravel residues in soils and swamps. (Source: African Diamonds plc)
Diamond mining in the Yengema area, Kono DistrictSource: Sierra Leone.org
- Artisanal mining around the town of Koidu-Sefadu, in Kono District on the eastern border with Guinea and Liberia. Mechanized alluvial mining at the Magna Egoli alluvial mine along the Sewa River between the towns of Bo and Kenema. The mine was developed and run by Rex Mining of Antwerp until 2002, when operations were taken over by Fauvilla Ltd. and Waldman Diamond Resources of Israel.
- Energem Resources Inc (Canadian, ENM.TO) has a 40% stake in Koidu Holdings SA (Magna holds 35% and BSGR holds 25%) which is developing the Koidu kimberlite project as well as exploring three alluvial concessions Matemu, Upper and Middle Sewa and the Tongo Fields Kimberlite Dyke Deposit. Koidu comprises two pipes and four dyke zones and has estimated indicated and inferred resources of 1,52 million t @ 0,55 carats per tonne on the No. 1 pipe and 2,9 million t @ 0,26 carats per tonne (indicated and inferred resources) at the No. 2 pipe. Production for 2006 amounted to 80 152 carats with an average value of US$ 233 per carat (see video). By the end of 2007, the government of Sierra Leone had formerly ordered the temporary closure of the country’s sole operating kimberlite diamond mine after illegal mining activities by artisanal diggers in Koidu Holdings’ concession area made it impossible to safely exploit the deposit.
- Cream Minerals Ltd (Canadian, CRMXE.OB, CRMXF.OB, CMA.V) entered into an agreement with Casierra Diamond Corporation ("CDC") and its wholly-owned subsidiary, Casierra Development Fund Inc. ("CDF") (collectively, Casierra") to earn an interest in production from two exclusive prospecting licence areas for diamonds and other minerals and metals in Sierra Leone. Cream has the option to earn up to a 70% interest in the property. Casierra has been working in Sierra Leone since 1993 and obtained its first prospecting licence on the Sewa River, which drains the Kono diamond area. Kono is an important centre of diamond production in Sierra Leone with a high percentage of gem quality diamonds coming from kimberlite and alluvial sources. Extensive alluvial diamond exploitation has been carried out upstream of the CDF licence. In late 1994, CDF obtained its second offshore special Exclusive Prospecting Licence at the mouth of two rivers with extensive alluvial diamond mining activity, the Moa and the Mano. In a report written for the Geological Survey of Sierra Leone "The Diamond Fields of Sierra Leone", Hall (1966), reports production from 1950 to 1965 on the section of the river above the Sewa River licence, as 42,000 cubic yards with an average recovered grade of 0,75 carats per yard. He further reports 64,000 cubic yards production at similar grade for the same period from the section downstream from the licence and suggests substantial reserves remain in these areas. Based on study of the Sewa River placers and minor sampling, Hall presents an estimate for the section of the river contained within the licence area. He suggests 2,900,000 cubic yards at 0,4 carats per yard for the channel gravels and 1,500,000 cubic yards at 0,4 carats per yard for the flats and low terraces. Cream reported in August, 2007, that its joint venture partner, Casierra Development Fund Inc ("CDF") had applied for mining licences covering 31 acres (12 hectares) within its diamond exploration licence on the Sewa River in Sierra Leone. This will enable the joint venture to continue bulk sampling and start small scale mining of alluvial diamonds and gold. If, as anticipated, the licences are granted, the joint venture will be in a legal position to sell any production results after submitting the gem stones to the Government of Sierra Leone for royalty payment and the Kimberley Process Certification.
- Mano River Resources Inc (Canadian, MNO.V) has created a new subsidiary Stellar Diamonds Limited to handle its diamond assets for which it plans to list on the Alternative Investment Market (AIM) in London within a year, the company announced on April 5, 2007. The company intends starting underground diamond production on the Kono kimberlite dyke joint venture with Petra Diamonds in 2008. Petra Diamonds has a 51% interest in the Kono Project. Diamond recovery from the first bulk samples from the Lion fissures commenced in June, 2006. Petra said in September, 2007, that test work had combined weathered, diluted and mixed underground diamondiferous kimberlitic material, which had yielded 2,809 diamonds, totalling 241.7 carats. The ten largest stones ranged from 7.2 carats down to 0.65. The work done then was too limited to determine a representative grade or value. Minerva Resources has a minority interest (24.5%) in the Lake Sonfon Diamond Project, operated by Manor River Resources. Mano River Resources has announced that reconnaissance work has confirmed the presence of macro-diamonds, one of which is classified as a clear white octahedral gemstone weighing 0.315 carats, and of kimberlite indicator minerals, within the Lake Sonfon JV area.
- African Diamonds plc (AFCDF.PK, also active in Botswana, Guinea) holds two exploration licences and a mining lease over a large tailing deposit. West African Diamonds plc (WAD) is a diamond focused explorer with operations in Sierra Leone and Guinea. Formed from the West African assets of AIM LIsted African Diamonds plc and recently acquire additional licences in Guinea. WAD contains a portfolio of development and advanced exploration assets across West Africa.
- River Diamonds plc (RVD.L) is exploring the kimberlite dykes at Panguma adjacent to the Tongon diamondiferous kimberlite dykes. The company estimates that the kimberlite dykes on the concession represent between 1-million and 1,2-million tons of kimberlite. At an average grade of between 50 and 70 carats per hundred tons, this represents between 500 000 ct and 840 000 ct.
- Sierra Leone Diamond Company Ltd and its wholly owned subsidiaries have assembled a portfolio of mineral rights in Sierra Leone, covering some 36,364 square kilometres, which rights include not only diamonds but in many cases also precious metals, base metals, iron ore, rutile, bauxite and rare earths. The focus is on the discovery of diamondiferous kimberlite deposits.
- Target Resources plc operates through its subsidiary Milestone Trading Ltd and its Sierra Leone subsidiaries. Its main objective is the recovery of alluvial diamonds and gold in the Kono district of Sierra Leone.
South Africa
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Diamond Mines of the World/South Africa (Kevin Hulsey-Jewelry)
"Independent South African diamond firms seek to block new law"
- Alexkor Ltd has been mining diamonds on land, along rivers, on beaches and in the sea along the north-west coast of South Africa.
Alexkor was established in 1989, when the State alluvial Diggings was taken over from the Government and transformed into the Alexander Bay Development Corporation. Since November 1992 Alexkor Limited has been run as a public Company with the state as sole share-holder. Over the life of the mine approximately 10,000,000 cts of gemstone quality diamonds have been recovered.
Alexkor has a lease to prospect for and mine diamonds in sea concession areas 1a, 1b, 1c, 2a, 3a, 4a, 4b and 9d as well as the adjacent surf zones. Approximately 100 different shallow water contractors are currently undertaking diver-based mining in the sub tidal concession areas. - "SA's Alexkor grinds to halt" (Source: Miningmx)
- De Beers operates the Finsch, Kimberley (retreating dumps), Cullinan, Kleinzee, The Oaks and Venetia mines.
- Finsch mine, established in 1961, produced 2,215,643 carats in 2005 at an average grade of 37,3 carats per 100 metric tonnes.
- The Kimberley retreatment plant produced 1,896,893 carats in 2005 at an average grade of 19,6 carats per 100 tonnes.
- Cullinan mine, established in 1902, produced 1,304,653 carats in 2005 at an average grade of 28,3 carats per 100 tonnes.
- "Rio Tinto bidding for Cullinan"
- In February, 2007, De Beers announced that it wanted to dispose of the Cullinan mine. De Beers said on 22 November, 2007, it had sold its historic Cullinan mine to a consortium led by Petra Diamonds for 1 billion rand ($147.5 million) in cash.
De Beers, 45 percent owned by mining group Anglo American Plc, said in February it planned to dispose of the loss-making mine.
The consortium comprises of Petra and Saudi-based investment firm Al Rajhi Holdings, each buying 37 percent stakes, with black-owned Thembinkosi Mining Investments owning the remaining 26 percent.
Petra estimates the total resource at some 212-million carats and said that the C-Cut reserve made up 133-million carats of that, the existing mining operations on the upper levels adding another 60-million carats and the tailings dams a further 16-million carats to 18-milion carats. Cullinan is estimated by Petra to have a remaining economic life of at least 20 years at a production rate of one million carats annually - Kleinzee mine, established in 1928, produced 1,014,132 carats in 2005 at an average grade of 15,7 carats per 100 tonnes.
- The Oaks mine, established in 1998, produced 85,766 carats at an average grade of 34,4 carats per 100 tonnes.
- Venetia mine, established in 1992, produced 8,515,045 carats at an average grade of 143,5 carats per 100 tonnes.
- The Koffiefontein mine, established in 1870, and which produced 123 505 carats in 2005 at an average grade of 6,8 carats per 100 tonnes, was sold to Petra Diamonds.
- De Beers is developing the Voorspoed mine in the northern Free State, which will produce about one million carats annually.
- Petra Diamonds operates four mines, Helam, Koffiefontein, Sedibeng and Star. Koffiefontein is an underground kimberlite pipe operation, with the rest being fissure operations.
The fissure mines were acquired when Petra merged with Crown Diamonds NL in May 2005. Since then, significant attention has been given to the integration of Crown and its mining operations into the Petra group, thereby enabling the group to focus on further increasing production. The acquisition of Koffiefontein from De Beers was completed in July 2007.
The mines produced 175,000 carats in the year to June 2006 and, with Koffiefontein, increasing production is expected for the year to June 2007 and beyond. Petra Diamonds announced a substantial increase in reserves and resources in South Africa on 8 Oct 2007: -An updated carat base of 9.33 million carats attributable (11.38 million carats gross), an increase of 101% on previous statement (May 2005: 4.64 million carats attributable) -In-situ value of US$1.5 billion attributable (US$1.9 billion gross) -JORC compliant attributable reserves increase 66% to 2.95 million carats (May 2005: 1.77m carats) -JORC compliant attributable resources increase 123% to 6.38 million carats (May 2005: 2.86m carats) -Increase due to the acquisition of Koffiefontein and additional kimberlite fissure units included in the total mineral resource
- SouthernEra Diamonds Inc operated the Klipspringer Diamond Mine which is located 250 km north of Johannesburg and 35 km south of Polokwane, the provincial capital of the Limpopo Province. The mine was built and operated by SouthernEra in a Joint Venture with Naka Diamonds, a Black Empowerment Group. SouthernEra holds approximately 57% of the project.
The mine was placed on care and maintenance in December, 2003 as a result of the strong South African Rand. The mining license in place with the promulgation of the Minerals and Petroleum Resources Development Act remains valid, thereby enabling easy resumption of mining activities.
In July 2006, a trial mining and bulk sampling program was approved. The purpose of the six month program, which required no significant capital investment, was the following:
* Review and improve the mining method
* Assess the impact of increased diamond prices since the mine was placed under care and maintenance
* Assess the ability to operate in a strong Rand environment
* To be in a position to re-open the mine in an improving foreign exchange environment
A total of 4007 carats were sold for an average price of US$ 100 per carat giving Klipspringer a revenue per ton of about $62. These results are very encouraging when compared to historical results achieved at the mine.
In the Limpopo Province, exploration advanced both the Hope and Clifton projects which are located along the same structural lineament that controlled the emplacement of SouthernEra’s well known Klipspringer and Marsfontein diamond mine kimberlite cluster.
The Clifton project consists of two Prospecting Permits measuring 1295 Ha and 3586 Ha which were awarded in May 2006. Reconnaissance stream sampling has thus far resulted in the discovery of probe confirmed high-interest kimberlitic indicator mineral anomalies which are being followed up.
The 935 hectare Hope Project hosts a substantial 4 hectare kimberlitic indicator mineral anomaly. Two additional prospecting permits for 10,887 and 736 hectares within the Greater Hope Project Area were awarded in April 2006. Reconnaissance stream sampling commenced over these areas.
SouthernEra has between 49% and 65% interest in properties within the Hope and Clifton projects. The properties are in joint venture with two Black Empowerment Consortia. 5% is held in trust for the relevant local community.
- Diamond Core Resources Ltd is active in the Northern Cape Province and involved in two kimberlite exploration projects, the Paardeberg East Project, situated 40 km west of Kimberley, and the Skeyfontein JV, located some 20 km south east of the town of Postmasburg. Through its acquisition of Samadi (SA) Pty Ltd, Diamond Core has three alluvial projects, Uitdraai and Silverstreams, some 10 km north of Prieska, and the de Kalk Project some 30 km east of the town of Douglas. It has also acquired the Sanddrift project from SouthernEra and Minex located near its Silverstreams project on the Orange River in the Northern Cape. Diamond Core will pay between 1 million and 5 million rand for the prospecting right depending on when it is transferred into its name, as well as pay a fee to explore the asset until the right has been transferred. Canadian-listed BRC Diamond Corporation had agreed to acquire South Africa's Diamond Core Resources to create a group exploring for gems in South Africa and Congo, the firms said on 5 July, 2007. After the proposed deal, in which BRC will acquire Diamond Core in exchange for shares, BRC shareholders will own 53 percent of the company and Diamond Core shareholders the rest.
- BRC Diamond Core eyes two targets
- Nare Diamonds Ltd (NHY.BE, Australian-80%, and the Schmidtsdrift Communal Property Association-20%) owns the alluvial Schmidtsdrift mine, comprising six contiguous farms along the western bank of the Vaal River, with a combined area of 320 km2. The indicated total resource is 48 million tonnes with an estimated 247,310 carats. Prospecting and trial mining activities started in 2001 and Nare re-commenced trial mining in April 2006, yielding 1584,02 carats by end June 2006, including a 235,03 carat diamond. Nare is also involved in the Kamfersdam tailings treatment plant, the Klipspringer Joint Venture with SouthernEra Diamonds Inc and the Groen River exploration project. Nare announced in August, 2007, that it was to change its name to Lonrho Mining ahead of a dual listing on London's Alternative Investment Market. Lonrho then had a 21.94% stake in Nare Diamonds.
The 235 carat diamond recovered at the Schmidtsdrift mine, April 2006- Afgem Ltd (JSE:AFG) currently has three dormant underground kimberlite fissure mines, two in the Northern Cape and one in the Free State that were acquired in June 2005. It paid Rex Mining R2,5m cash, R25m in shares and set up an agreement to pay four percent of revenue on rough diamond sales up to 2021. Simolotse Mine, previously Loxton Exploration, has indicated reserves of 155 000 tonnes @ 85cpht and inferred reserves of 238 000 tonnes @ 85cpht. The other two are Bokang Mine, previously known as Bellsbank Consolidated Diamond Mine, and Agisanang Mine, previously known as Rex Diamond Mine. Operations at Simolotse, which was the flagship operation, were suspended in March 2006. Flooding delayed the development of the critical number two shaft, hobbling cash flows and causing management to mothball the mine. Pumping and maintenance costs Afgem about R400,000 a month during the rainy season. Bokang, also an underground mine, is also not producing because of flooding. The third mine is the Agisanang mine between Welkom and Theunissen in the Free State province. It was shut in 1998. The mining licence has passed to another group, but Afgem is pursuing it retrieval.
In March, 2007, Afgem requested trading in its JSE-listed shares be suspended because of financial difficulties, but was in talks with a potential buyer of two of its mines, failing which it could possibly restart mining after a re-capitalisation process.
- Pangea Diamond Fields plc is exploring and bulk sampling in the two target areas of the Malmani project which were identified from drilling and the overburden is in the process of being stripped. Once underlying gravel horizons have been subsequently exposed, the gravels will be processed to test for diamonds and a resource will be estimated. The Patsema drilling program, which is testing gravity targets, is in progress with 101 holes having been drilled to date. The existence of significant gravel-filled pothole structures has been indicated and this program will be followed by bulk sampling. The company announced in May, 2007, that it had delineated at least 34 million tonnes of potential diamondiferous gravel from more that 800 boreholes that had been drilled to date at its Bakerville Project area and was testing a 21 million ton gravel deposit at its Malmani Project area. At its Patsema Project area it had investigated less than 10 percent of the licence area and five potholes with an aggregate of at least 1,5 million tons of pothole gravel had been delineated from exploratory drilling. [more]
- Rockwell Ventures Inc (Canadian, RVINF.OB, RVI.V) acquired a 51% interest in H C van Wyk Diamonds through the purchase of Durnpike Investments (Pty) Ltd. completed early in 2007, and began receiving revenues from the operations in January 2007. The Company plans to increase its equity ownership in the Van Wyk operations from 51% to 74% in the first half of 2007, concomitant with an inward listing on the Johannesburg Stock Exchange. Van Wyk Diamonds is working the alluvial deposits at Holfontein-Klipdam, 45 km from Kimberley and at Wouterspan, near Prieska, respectively. The inferred resource at Holfontein-Klipdam is 12 million cubic metres at a grade of 1,16 carats per 100 cubic metres and the total inferred resource at Wouterspan is 46 million cubic metres of gravel. On March 6, 2007, Rockwell and Trans Hex Group Limited announced that the companies had entered into an agreement whereby a wholly owned South African subsidiary of Rockwell could acquire two open pit alluvial diamond mines and three alluvial diamond exploration projects from Trans Hex. The two open pit alluvial diamond mines, namely Saxendrift and Niewejaarskraal, and the three alluvial diamond exploration projects, namely Kwartelspan, Zwemkuil-Mooidraai and Remhoogte-Holsloot, are located along the southern bank of the Middle Orange River between Douglas and Prieska in South Africa and are collectively referred to as the "Middle Orange River Operations". Rockwell's Wouterspan alluvial diamond operation is located on the north bank of the Middle Orange River, immediately adjacent to the Saxendrift and Niewejaarskraal diamond mines. Rockwell also has rights to the diamondiferous gravel on the farm Galputs 104 in the Northern Cape Province. The company announced in May, 2007, that it had concluded the purchase of the Makoenskloof alluvial diamond project, located on the north bank of the middle Orange river, 40 km upstream of its Wouterspan diamond operation. Rockwell entered into an option with Kanonloop Delwerye early in 2007 to evaluate the alluvial diamond potential of the Makoenskloof project. Rockwell has set ambitious targets of more than doubling its current production to as much as 80 000 ct/y by 2011.
- Tawana Resources NL (Australian, TWNAF.PK, also active in Botswana) is exploring alluvial gravels in palaeochannels in the vicinity of the Finsch diamond mine, drilling kimberlite targets in the same area and exploring the known kimberlites at Perdevlei and Kareevlei West. The indicated grade at Perdevlei is 15-20 cpht. Transhex holds an option to acquire 35% of the project, exercisable 6 months after a decision to mine has been made, for the payment of 3,5 times the costs incurred by Tawana in establishing the viability of, and bringing into production, a diamond deposit. Kareevlei Wes project comprises a cluster of 5 kimberlite pipes, which vary in surface area from a large 5,8 ha to 0,3 ha. Drilling to a depth of 100m showed that the tonnage of KV3 is 13 million t and that of KV2 is 2 million t. Previous work showed that three of the kimberlites, KV1, KV2 and KV3 are diamondiferous. Bauer drill bulk sampling of KV1 and KV2 showed that these two kimberlites have a similar estimated grade of 8,5carats per 100 tonne. Tawana announced in April 2007 that it had entered into a joint venture with Guma Resources, its strategic alliance partner, to explore and mine the Lexshell alluvial diamond project in the Northern Cape. The project, located on a palaeo-channel of the Vaal river, is held under a mining right by Lexshell 366 Mining. Tawana announced on 15 May 2007 that it had entered into a joint venture with Taormina Mining to prospect and evaluate a kimberlite situated 25 km north of Kimberley. The kimberlite was a four hectare pipe known locally as the Riverton mine and was reported to have produced good quality diamonds when it was mined by small scale diggers during the 1990s. Tawana was able to earn 51% equity in the project by conducting a 2 000 t bulk sampling programme, followed by an 8 000 t evaluation program if warranted. Thereafter, it had the option to increase its equity to 70% by paying Taormina R1,5-million. Tawana also acquired a 30% interest in the St Augustines kimberlite which is located some 600 m west of the famous Kimberley mine - the Big Hole. The Big Hole produced 14,5-million carats of diamonds from 22,5-million tons, at a grade of 64 carats per hundred tons. Mining at the Big Hole stopped in 1914. Tawana said in a statement that the St Augustines kimberlite was mined in the late 1890s and records showed that the diamond quality was considered identical, and the grade similar, to that of the nearby Kimberley mine. Records show that St Augustines was only partially mined to a depth of about 240 m, and mining stopped at the site in 1902.
- Caledonia Mining Corporation holds a prospecting and option agreement over the Goedgevonden diamond bearing kimberlite pipe located approximately 20 kilometres north of the Stilfontein Gold Mine in the Klerksdorp district of the North West Province. To date there has been insufficient work on the Goedgevonden property to define a resource for the property.
- Etruscan Resources Inc and Mountain Lake Resources Inc formed a new company Etruscan Diamonds Limited to hold their respective interests in their diamond assets in South Africa. Etruscan and Mountain Lake own 62% and 21% respectively of Etruscan Diamonds with the balance being held by various third parties. Over the last five years, Etruscan South Africa has been acquiring strategic properties in the Ventersdorp Alluvial Diamond District, located approximately 150 kilometers west of Johannesburg and holds the dominant land position in the Ventersdorp District with two mining permits and 16 prospecting permits with applications for 5 additional prospecting permits pending. The Hartbeestlaagte property covers approximately 4,000 hectares and is located approximately 35 kilometers due north of the town of Ventersdorp. Etruscan South Africa has completed three bulk samples on the Hartbeestlaagte property, processing over 78,000 cubic meters of Lower Gravel Package ('LPG') gravels and recovering approximately 2,500 carats at a global grade of 3,18 carats per hundred cubic meters with a bottom cut-off size of 1.6 millimeters. A limited amount of Upper Gravel Package was also processed (approximately 12,000 cubic meters) to recover 187,7 carats at an average grade of 1,53 carats per hundred cubic meters. The treatment of the bulk samples was by a process of scrubbing and screening followed by pan concentration and x-ray sorting. The in situ inferred diamond resources are estimated in the 43-101 report to be 16,2 million cubic meters of LGP gravels at an average grade of 3,18 carats per hundred cubic meters (approximately 500,000 carats) at an average sales value of USD$400 per carat. The 43-101 report confirms that, in addition to the inferred resource, a large area of exploration potential exists in both the lower gravel package and the upper gravel package including an indefinable volume of material that is located below the present drilling level in the sink holes. Drilling to date has been limited to a vertical depth of 117 meters in these areas. Etruscan Diamonds completed the acquisition of the 50% of Tirisano Diamond Mine it did not already own from Mvelaphanda Exploration in October, 2007.
The Tirisano Diamond Mine is located adjacent to the Hartbeestlaagte property where Etruscan Diamonds is presently undertaking a pre-feasibility study. Etruscan announced in February, 2008, that Etruscan Diamonds (Pty) Ltd. had received a National Instrument 43-101 compliant independent resource update on its Blue Gum Diamond Project in South Africa which substantially increases the resource on the project. The independent resource update prepared by Dr. Tania Marshall of Explorations Unlimited estimates that the Blue Gum Diamond Project contains 20.5 million cubic meters of indicated diamond resource and 17 million cubic meters of inferred diamond resource. The Blue Gum Diamond Project consists of three adjacent diamond properties (Nooitgedacht, Hartbeestlaagte and Zwartrand) covering over 10,000 hectares located in the Ventersdorp Alluvial Diamond District with the Tirisano Diamond Mine being located on the Nooitgedacht property.
- DiamondCorp plc is developing the Lace project, located 20 km from Kroonstad in the Free State Province. The project contains an estimated 14 million carats of diamonds in tailings and kimberlite. Additional kimberlites have been identified on the group's adjoining properties. The company has an option to acquire Sonop Diamond Mining (Pty) Limited for US$45 million cash and 7.5 million ordinary shares of 3 pence each in the capital of DiamondCorp plc. Sonop has large-scale alluvial diamond mining operations along the Vaal River and Middle Orange River in South Africa and produced over 93,000 carats of high-quality gem diamonds during the year ended 28 February 2007.
- KimCor Diamonds plc is a mining company owning and operating a suite of diamond mining and exploration properties that include underground, alluvial and dump processing operations complemented by a diamond cutting and polishing business. KimCor was admitted to AIM in March 2006, and raised approximately £3.35 million for expenses for the construction and development of a diamond recovery plant to process tailings at its Bellsbank site. n September 2007, KimCor completed the reverse takeover of Dwyka Diamonds Holdings Limited, a subsidiary of Dwyka Resources Limited ("Dwyka") and acquired Dwyka's four producing mines and a number of advanced exploration projects.
At the time of it's original listing, KimCor's projected diamond production from its Bellsbank operation was approximately 50,000 carats per annum. With the acquisition of Dwyka's producing assets and following a number of capital projects designed to increase production rates on all operations, total diamond production is scheduled to progressively increase to 200,000 carats per annum.
The two underground mines, Blaauwbosch and Newlands generate a high percentage of stones in the 1 to 5 carat size range that provide an ideal product for the value added process of cutting and polishing provided by Anmic, a subsidiary in which KimCor, through its subsidiary Free State, holds a 50 per cent interest and an option to acquire the balance of equity. Bellsbank and SMI4 Superkolong, the two dump reprocessing operations are low cost bulk mining projects producing large quantities of lower value diamonds predominantly for export. Nooitgedacht, the one alluvial operation which also supplies sand and aggregate as a by-product from diamond mining, has a long history of producing large high-value diamonds including the Venter diamond, the largest recorded alluvial diamond recovered in South Africa at 511 carats.
- Bonaparte Diamond Mines NL has Joint Venture agreements with a South African Company, Universal Exploration Technologies (Pty) Ltd, for the acquisition of two prospective kimberlite exploration projects located in the Free State Province of South Africa. Prospecting Permit (PP) applications for these project areas are pending approval. The agreements include an option for Bonaparte to acquire a 60 % interest in each of the Projects. Mofschaap:
The Mofschaap Project covers an area of approximately 465 hectares and is located adjacent to the Lace Diamond Mine which reportedly had a historic production of some 700,000 carats. The Voorspoed Mine lies approximately 6km to the northeast of the project. The area is considered prospective for structurally controlled kimberlitic intrusions, given its location in respect to known kimberlite occurrences.
Bronkhorstfontein: The Bronkhorstfontein Project covers an area of approximately 780 hectares and lies some 20 km south of Heilbron in the Free State. Although there are no known kimberlites in the immediate area, previous exploration over a small portion of the area is reported to have identified a magnetic anomaly from which follow-up sampling gave positive kimberlitic indicator minerals.
History
Although it is often thought that Dr Williamson discovered Tanzania’s first diamonds, the Williamson mine was in fact preceded by several tiny operations,including the Mabuki mine which Williamson worked on and later owned. Williamson eked out a meagre living from Mabuki, which he used as the base for his prospecting operations in what was then known as Sukumaland. In 1940 in the Shinyanga area, around 160 km south of the town of Mwanza on Lake Victoria, he discovered the kimberlite, which would make his name world famous. The site of the mine was named Mwadui – after a local chief – and in the years since the names “Mwadui” and “Williamson” have become virtually synonymous. With the Second World War in progress and with Williamson himself having few resources, development at Mwadui was initially slow but, by the 1950s, a formidable mine had emerged. The total staff and labour force numbered several thousand and included around 400 expatriates, mostly from the UK and South Africa. Williamson made his home at Mwadui and managed the operation very closely. Mining equipment included draglines and scrapers while a succession of treatment plants were built, the first being a pan plant running at a grade of 62 cpht. A notable innovation in the late 1950s was an HMS plant, which ranked as the first in the world in the diamond mining industry.
Geology
The Mwadui kimberlite was discovered in 1940 by Dr John T Williamson and is the largest primary deposit of it’s kind in the world ever to be mined, measuring some 146 ha at surface. This Cretaceous-aged kimberlite has been mined continuously as an open cast operation since it’s discovery. The Mwadui kimberlite can be subdivided into five major and distinct rock types, viz. the Shale Basin, the Bouma Facies, Granite Breccias, Reworked Volcaniclastic Kimberlite types (RVK), and primary Pyroclastic Kimberlite (PK). The Shale Basin represents a phase of lacustrine sedimentary deposition towards the end of the in-fill cycle of the crater and forms the upper part of the central depositional crater. Diamond grade is extremely low and the material has been avoided during mining. The Bouma facies represents the lower part of the central depositional crater and is distinguished from the Shale Basin by the presence of Shale Basin by the presence of Bouma sequences. Diamond grades of this material are generally low. The lower contact of the central depositional basin is characterized by a substantial Granite Breccia zone. These deposits formed after the final eruptive episode, mainly as a result of collapse of fractured and unstable crater walls, comprising basement granite. The breccia units are characterized by a large range in intermixed volcaniclastic material, resulting in material containing nearly barren to economic diamond grades. The Reworked Volcaniclastic Kimberlite (RVK) deposits were formed in response to reworking of the primary tuff ring deposits as a result of grain flow and debris/avalanche deposits into the open crater. Wall-rock dilution is relatively low compared to some of the other units, resulting in high diamond grades. The material below the RVK can collectively be referred to as Pyroclastic Kimberlite (PK) and can only be observed in the deeper sampling tunnels and drill holes. The kimberlite exploited the existing joint and fracture system during emplacement and the northern and southeastern parts of the crater terminate into hypabyssal facies dykes. The northern dyke can be classified as a macrocrystic monticellite kimberlite with variable phlogopite and microlitic diopside. The southern dyke is poorly exposed and highly weathered. (Source: De Beers)
One of the world’s legendary diamond mines, Tanzania’s Williamson Diamonds Limited is still going strong, 60 years after being established by Canadian geologist, Dr John Williamson. Williamson Diamonds Limited is situated in the town of Mwadui and in the province of Shinyanga, 130 km from the city of Mwanza in Tanzania. The mine has been through an illustrious past and was managed from the early 1970’s to 1994 by the Tanzanian Government. (Source: De Beers)
- was invited back in the early 1990’s to manage the Williamson mine and today Williamson Diamonds Limited is owned 75% by De Beers through Willcroft Co Ltd – Bermuda (a De Beers subsidiary), and 25 % by the Government of Tanzania. Mahene kimberlite, which sub-outcrops over an area of around 6,8 hectares, and the Itanana kimberlite, the smaller of the two Tanzanian kimberlites, measuring between 2,0 and 2,3 hectares in sub-outcrop. Previous but limited drill-core sampling (53 tonnes) by De Beers returned a diamond grade of approximately 8 carats per hundred tonnnes for Mahene and a sampling grade of 3 cpht for Itanana.
- Petra Diamonds of South African secured a US$78 million loan to fund the expansion of its Williamson diamond mine in Tanzania and Cullinan mine in South Africa in June, 2010.
The loan is part of a $78 million debt it negotiated with International Finance Corporation (IFC), a World Bank financing arm, and the Rand Merchant Bank (RMB) to expand the Williamson diamonds mine and Cullinan Mine in South Africa.
In terms of the agreement, Petra would receive $40 million from the IFC and $38.7 million from RMB over a five-and-a-half year debt facility.
The RMB loan would mainly be used to expand the Cullinan mine, but could also be applied towards other operational expenses.
The Williamson's mandate includes an expansion programme to increase output from an average of two-million tons a year to 10 million tons a year.
The production expected to increase at an average grade of 6 carat (ct) for every hundred tons would yield an estimated yearly production of some 600 000ct.
According to Petra Diamonds CEO, Johan Dippenaar, the Williamson mine at Mwadui, in Shinyanga, Tanzania, expansion plan is estimated to take up to three years to complete. Petra, a leading supplier of rough diamonds, said the expansion project is expected to commence in the second half of this year after completion of bulk sampling operations that will end this month.
The company said in its annual report at the end of March that revenues from bulk sampling activities improved in line with the general improvement in diamond prices.
The company was recorded a price of $172 per carat in the latest tender - 24,441 carats - in February 2010, a significant improvement on the average for the six months to 31 December 2009 of $141, and in line with management's expectations to improve the recoveries and associated diamonds values.
Petra acquired 75 per cent interest in the Williamson diamond mine in November 2008 - a mine renowned for producing high value diamonds.
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Zambia
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- Caledonia Mining Corporation has a joint venture agreement with Motapa Diamonds Inc (‘Motapa’) and BHP Billiton World Exploration Inc., together as the ‘BHP Entity’ on the Mulonga Plain and Kashiji Plain licenses in Western Zambia. Motapa is the project operator on behalf of the joint venture and has a 60% participating interest in the project, with Caledonia holding a 40% interest. BHP Billiton holds no interest in the project but retains a back in right on Motapa’s interest. In terms of the joint venture agreement, Caledonia’s interest will drop to 25% in the event that Motapa and BHP Billiton continue to sole fund the project to completion of a feasibility study.
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Zimbabwe's diamond industry commenced with the discovery of alluvial diamonds in 1903 followed by the discovery of the first diamondiferous kimberlite pipe, Colossus, in 1907. There are more than eighty known kimberlite bodies in Zimbabwe, most discovered by Rio Tinto and De Beers. Zimbabwe's first diamond mine, River Ranch, commenced production in the early 1990's. Currently the bulk of Zimbabwe's diamond production is from Rio Tinto's Murowa diamond mine.
Zimbabwe Government Seizes Marange Diamond Mines
Zimbabwe to Nationalize Diamond Mining After Gem Rush
- RioZim owns 22 percent of Murowa diamond mine, while Rio Tinto, the former parent company, owns the remaining controlling stake. The mine saw 2006 production down to 240 026 carats from 251 000 carats of diamonds in 2005. RioZim told shareholders the fall was a result of a weaker surface ore body and worsening power cuts. RioZim said the diamond dip had been expected. Rio Tinto, which has been in Zimbabwe's mining sector for 50 years, has spent $100m expanding its Murowa Diamonds since the discovery of diamonds 14 years ago.
The operation, which is 77,8% owned by Rio Tinto, is capable of producing 300,000 carats/year of diamonds.
- SouthernEra has a joint venture agreement with Rockover Resources Limited over the Tsholotsho Diamond Project in Zimbabwe and involved in early stage exploration. The Tsholotsho Diamond Project is situated in western Zimbabwe and consists of 21 granted and a further 7 under application prospecting permits covering an area in excess of 14,000 km² underlain by basement Archaean granite-gneiss of the Kalahari Craton. The Botswana/Zimbabwe border forms the western boundary of the permit area. This project area is considered prospective for primary diamondiferous kimberlite deposits and lies within what is known as the Orapa Kimberlite Track, which is a southwest – northeast trending kimberlite emplacement corridor extending from Botswana into Zimbabwe.
- African Consolidated Resources plc said in March, 2007, that Zimbabwe's government has ignored a high court ruling to allow staff back on to the premises at the expropriated Marange diamond mine. Police guarding the mine have not let staff back on site. The government was to negotiate an agreement over the expropriaton, but had failed to do so. African Consolidated is thought to have lost up to $2m when diamonds it had produced and had on site were seized by the governmen and auctioned by Mineral Marketing of Zimbabwe. African Consolidated Resources announced a loss in revenues in excess of US$1 billion as a result of illegal extraction and trade activities following the company's expulsion from the Marange mine in Zimbabwe early in 2007.
Since ACR was expelled from Marange it is believed that more than 7,000 carats valued at approximately US$1 billion have been lost as a result of diamond smuggling which allegedly involves security forces, according to local news source The Financial Gazette (Harare).
Zimbabwe Mining Development Corporation (ZMDC), which has started mining at Marange, has been criticized by Central Bank Governor, Gideon Gono for what are seemingly mechanized panning activities. Critics have stated that in order to derive a genuine benefit from diamond mining in Marange, ZMDC will have to employ a technical partner that has the appropriate equipment and technical knowledge.
The dispute over the ACR diamond claims against the government now involve Amos Midzi, Mines Minister; the Mineral Marketing Corporation of Zimbabwe, the ZMDC, the Mining Commissioner and Police Commissioner Augustine Chihuri.
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