He said someone had discovered diamonds in the host rock while trying to make thin section slides. Examination of the slab at this point allowed discovery of the first Colorado diamond. He stated that at the time two or three kimberlite pipes had been discovered and claimed, but he knew personally of at least a couple more. Later on, Howard Bachman of Lakewood and several others made trips to one or more of the pipes to prospect. One rockhound found a chrome pyrope garnet chunk several inches long that I got to see.
Chrome pyrope is one of the more common accessory minerals frequently found in kimberlite.
An article in the Denver Post July 19 stated that the Kelsey Lake diamond prospect north of Ft. The larger of the two is rated the 6th largest diamond ever found in No. America. Howard Coopersmith, the mine's discoverer, reports that the mine is recovering dozens of smaller diamonds per day. To date, in fact, about 20,000 stones, two-thirds large enough to cut into jewelry stones. The mine holds an estimated reserve of one million carats of diamonds, and the life expectancy of the mine is about 12 years.