After many years of virtually fruitless exploration, northern Colorado may yet see a viable diamond mine.

A cluster of kimberlite deposits near Kelsey Lake near the border with Wyoming could become a working diamond mine by the end of the decade, says Howard Coopersmith, president of Diamond Co. NL of Ft. Collins, Colo.

Redaurum Ltd. of Toronto, Canada, bought a controlling interest in Diamond Co. last year and has approved construction of a processing plant to handle 250,000 tons of kimberlite yearly in the preproduction phase of the mine. The plant could be expanded to a million tons yearly if the mine goes into full production (that’s about a fifth of the capacity of De Beers’ large mines and about half its smallest mine).

The Kelsey Lake cluster consists of two larger kimberlite pipes and four smaller ones – all of them diamondiferous, says Coopersmith. He says the four smaller pipes would be economical to mine if operated in conjunction with the two larger pipes.

Coopersmith says he discovered the pipes in 1987 and has extracted small samples in successive stages since then. “Overall,” he says, “we’ve found at least 60% of the diamonds can be cut into gems, including one diamond of 14.2 carats.” Coopersmith is still working out the ore grade and value tables.

Contrasts: This project contrasts sharply with another North American diamond project – the BHP mine in Canada’s Northwest Territories (see following story). The Colorado mine is much smaller than BHP’s, which analysts say will produce hundreds of thousands of carats annually and which has spawned a diamond rush.

It also is being developed more slowly. “We’ve had to raise the money for each stage of exploration and testing,” says Coopersmith. “We’ve spent about $2 million thus far. BHP spends that in a week. Secondly, there’s been no rush by other companies because this area has been explored and given up before.” In fact, mining companies have been combing the border between Wyoming and Colorado for 20 years and have found too few diamonds to make a go of commercial mining.

On the plus side, he says, this project should be less costly because it’s more accessible and won’t have to contend with the extreme weather that hinders development of the Canadian mine. “You can basically drive to this site,” he says.

The company still is looking at ways to market diamonds should the mine go into production. Redaurum also mines the River Ranch diamond deposit in Zimbabwe and ships all of that production to Antwerp for periodic tender sales. “Thus far, that has been quite successful,” says Coopersmith.


Reports from the BHP Minerals/Diamet diamond mining project in Canada keep getting better.

The mine, now under construction in the Lac de Gras area of Canada’s Northwest Territories, was planned around a cluster of three diamond-bearing kimberlite pipes. Recent samples proved that two nearby pipes also would be economical to mine, says BHP. As a result, the mine’s estimated life span has been increased from 20 to 25 years.

BHP says kimberlite extraction should total 9,000 metric tons daily at first and rise to 18,000 tons daily by the 10th year of operation. Production is scheduled to begin in the third quarter of 1997, pending approval by local and national government agencies. The project is now under review by a government environmental panel and local tribes, which hold some autonomy in the area.


An industrial park for small diamond-polishing operations has opened in Gujurat State just south of Surat, India’s diamond processing center. The park offers a customs-free zone, security facilities and delivery vans for the polishers working there, reports D. Wickramanayake, JCK Asian correspondent.

The facilities are designed to help smaller manufacturers and individual polishers who want to go into business for themselves. Sevantilal Shah, vice president of the Surat diamond manufacturers association, says the park should help improve Surat’s polishing industry.

But elsewhere in Gujurat, labor unrest and shortages of rough diamonds threatened to shut down about 400 small polishing plants.

C.R. Prabhakaran, president of the Kerala Diamond Artisan’s Association, says 30 firms have closed because of year-end strikes. Workers demanded permanent employment, days off for national holidays and paid leave. Shortages of rough threatened hundreds of other operations, which require about 50,000 carats monthly to stay in business.

Many of these shops serve as subcontractors for larger manufacturers, most of which are suffering from bloated inventories and stagnant sales.

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