Diamond Mines of the World: Australia
Australia's Argyle Diamond Mine
Article Copyright © 2009 AllAboutGemstones.com
The Argyle diamond mine is located in the Kimberley region of Western Australia, south-east of Wyndham, between Hwy 1 and Lake Argyle, in the northern part of the country. The Argyle mine is the first commercial diamond mine dug along an olivine lamproite volcanic pipe rather than a kimberlite pipe. The Argyle volcanic pipe is a diatreme (breccia filled volcanic pipe) formed by gas or volatile explosive magma which has breached the surface to form a "tuff" (consolidated volcanic ash) cone. The Argyle mine also has alluvial mining operations.
The Argyle mine is the largest "raw" diamond producer in the world, but a low percentage of Argyle's yield (around 5%) is gem-quality. The worldwide average for a diamond mine's yield of gem-quality stones is around 20 percent. The remaining 95 percent of Argyle's production is classified as "near gem quality" or "industrial grade," which is used in abrasives and other industrial applications.
These under-appreciated stones are also gaining favor with contemporary jewelry designers who use them in their natural state in raw diamond jewelry.
Arglye is owned by Anglo-Australian mining titan, the Rio Tinto Group (60% ownership), which also owns stakes in the Diavik Diamond Mine in Canada, and the Murowa diamond mine in Zimbabwe. Ashton Mining has the remaining 40% ownership in Arglye. In 1996 Argyle turned the De Beers distribution monopoly on its head by going-it-alone, bypassing De Beers' Diamond Trading Company DTC/Sightholder wholesale network, selling directly to the Antwerp diamond Bourses.
Argyle Diamond Mine (Photo, Left: Public Domain)
Australia's Argyle pipe diamonds are approximately 1.5 billion years old, while the volcano which created the pipe is around 1.1 billion years old, making Argyle diamonds some of the youngest on earth. This 400-million-year gap between creation and volcanic deposition represents a relatively short period for diamond formation. This short gestation period could explain the small size and unusual physical characteristics of Argyle diamonds.
The mine produces 80% brown diamonds, 16% yellow diamonds, 2% white diamonds, and the remaining 1% are pink or green. Argyle diamonds fluoresce blue or green under ultraviolet light and the most common inclusions are graphite piquŽ, crystalline orange garnet inclusions, pyroxene, and/or olivine. Of particular interest is the tantalizing possibility that the carbon found in Argyle diamonds is mostly organic in origin.
Argyle Pink Diamonds
Known for its fancy colored diamonds, Australia's Argyle Mine is one of the world's only major sources for rare pink diamonds which are similar to pink sapphire in color, yet considerably more expensive. Despite the low percentage of pink diamonds, about 90 percent of the world's pink diamonds are from the Argyle mine. Perhaps the most elusive of the fancy diamond colors (even for Argyle) is the natural red diamond, with as few as twenty known specimens in existance.
Bibliography on Australian Diamonds
1. BHP Billiton, Ekati Diamond Mine  . www.ekati.bhpbilliton.com
2. Mining Technology, New Techniques in Mining Technology . SPG Media Group PLC
3. Mining Technology, Ekati Diamond Mine . www.mining-technology.com
4. Aurias, Diamonds from the Ekati mine . www.aurias.com
5. Diavik, The Diavik Diamond Mine . www.diavik.ca
6. GIA, Gemological Institute of America . www.gia.edu
7. AGS, American Gem Society . www.ags.org
8. Southern Era, Southern Era Diamonds - Canada Projects . www.southernera.com
9. Trigon, Trigon Uranium Corp - Canada Diamond Projects . www.trigonuraniumcorp.com
10. Fred Cuellar, How To Buy A Diamond 5th Edition . Sourcebooks Casablanca
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