Firestone Diamond Mining
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[edit] Avontuur Mine, Namaqualand, South Africa
Firestone's Avontuur Mine is located near the coastal town of Hondeklip Bay in Namaqualand. Hondeklip Bay is a well established alluvial diamond producing area and hosts De Beers' Koingnaas Mine and Trans Hex's Hondeklip Bay Mine. These mines have been producing diamonds for 20 years and 15 years respectively and are estimated to have yielded in excess of 10 million carats with an estimated value of over $1 billion at current market prices. Firestone has recently completed a major expansion programme at the Avontuur Mine, resulting in the integration of two previously separate and adjoining operations on the Nova and Gras Kom properties into a single expanded operation centred on the Avontuur Mine.
Earthmoving capacity has been more than doubled to over 1 million tonnes per annum, gravel treatment capacity has been increased by 60% to approximately 320 tonnes per day, and exploration drilling capability has been increased ten fold.
Recent drilling on the mine has also led to the discovery of a number of new gravel deposits, and while further evaluation of these deposits is required, the Company is confident that they will result in an increase to the mine's reserves.
Diamonds produced from Avontuur average approximately 0.2 carats in weight and more than 80 per cent are of gem quality and good, white colour. The largest diamond recovered to date weighed 1.9 carats. Firestone markets its diamond production independently of the CSO by private tender, and sales are held several times a year in South Africa. The high quality of the Avontuur gem stones ensures that Firestone receives better than average prices for its diamonds, and in recent sales prices have averaged between $100 and $110 per carat
[edit] Oena Mine, Namaqualand, South Africa
Firestone acquired an 87.5% interest in the Oena Mine in February 2000, and is in the process of re-establishing mining operations at the mine. The Oena mining lease covers an area of 8,800 hectares and extends for 17 kilometres along the banks of the lower Orange River. The Orange River played a very significant role in the creation of the alluvial diamond deposits on the west coast of Southern Africa. First, it was the largest and most important river which transported diamonds to the west coast. Second, it carried diamonds of a size and quality considered equal to best in the world, with average values of between $700 and $900 per carat. Asam Minerals, Firestone's geological consulting affiliate, carried out the first prospecting activities on the lower reaches of the Orange River in the late 1960's, and was responsible for the discovery and development of the first mines on the lower Orange River at Octha and Baken.
Octha is estimated to have produced 700,000 carats, with a current value of $500 million. Baken, which is considered to be one of the premier alluvial diamond mines in the world, is the flagship of Trans Hex, South Africa's second largest diamond producer, and has been producing for over 30 years. Baken currently produces approximately 50,000 carats per annum, with a gross value of about $40 million. De Beers' Auchas Mine is located opposite Baken on the Namibian side of the Orange River and currently produces 25,000 carats per annum. The Oena Mine is located approximately 17 kilometres upstream of Baken. Upstream of Oena, Global Diamond Resources, a US listed company, is developing a mine at Grasdrif. Trans Hex is carrying out a feasibility study at their Northbank project, located on the Namibian side of the river opposite Grasdrif.
Previous mining operations at Oena in the early 1990's were small scale and focused on two remnant deposits of high grade Miocene-age gravels, known as proto Orange gravels. Between 1991 and 1995, Oena produced approximately 30,000 carats, worth about $24 million at current prices. The average stone size was approximately 2 carats, and in 1993 production was sold for an average of $880 per carat. The largest stone recovered was 79 carats. As prices of large, high quality stones have increased significantly since then, the current market value of these diamonds is estimated to be in the region of $1,000 per carat. By 1995 the proto Orange gravels at Oena were mined out, following which mining operations were suspended.
Firestone intends to re-establish mining operations at the mine to exploit the substantial resource of more recent gravel terraces, known as meso Orange gravels, which remain on the mine. Geological and topographical mapping, aerial photo analysis, and drilling have been undertaken on the meso terraces, on the basis of which the total gravel resource is estimated to be approximately 40 million tonnes.
Sampling on the meso terraces has produced grades between 0.6 and 1.25 carats/100 tonnes, with localised high grade areas of between 5-10 carats/100 tonnes. Over 330 carats were recovered from small scale subcontracting operations at Oena in 1999, which were sold at an average price of $880 per carat. The largest stones recovered were 48 carats, 16.28 carats, and a 10.81 carat D flawless stone which sold for $5,000 per carat.
Oena has the significant advantage that much of the original mine infrastructure is still in place, allowing production to begin almost immediately. Key elements of the infrastructure include mining equipment, more than 1,300m2 of accommodation, office space and workshops, fresh water supply, telephone line, 1,300 metre runway, and gravel treatment plant and sorting building.
Oena also has significant exploration potential, as it is believed that high grade proto Orange gravels have been preserved beneath the meso Orange gravels in certain locations at the mine.
