While the United States is the leader in diamonds purchased, there are relatively few diamonds actually mined domestically. There are numerous kimberlitic pipes and lamproite pipes scattered from New York to Wyoming and Michigan to Arkansas, there are currently only two active diamond mines in the country.

Kelsey Lake
The Kelsey Lake Diamond Mine, which straddles the Colorado-Wyoming State line, began production in 1996. It was North America�s first large-scale commercial diamond mine. Largest diamond found so far is 28.3 carats, and about 25% of the 20,000-carat annual production is of gem quality. Kelsey Lake, the United States� only commercial producing diamond mine, is now owned by McKenzie Bay International, Ltd, a Canadian mining company, and is operated by McKenzie�s local subsidiary, Great Western Diamond Co.

Crater of Diamonds
It is located 2.5 miles south southeast of Murfreesboro, Arkansas, diamonds were discovered in 1906 by a local farmer. The lamproite pipe was mined from 1910 through 1929 and was a private tourist attraction from the 1950s to 1972, when it was sold to the state and converted into Crater of Diamonds State Park. It has been estimated that over 100,000 diamonds have been recovered from the field. This site holds the record for the two largest diamonds found in North America; The Uncle Sam (40.23 carats rough) and the Star of Murfreesboro (34.25 carats rough).