Although diamonds are the most popular gemstone with United States consumers, domestic production of diamonds is very low. There is currently only one active diamond mine in the United States. This is at Crater of Diamonds State Park near Murfreesboro, Pike County,Arkansas. There, recreational prospectors have been finding a few hundred carats of diamonds per year since the early 1970s. However, this is a tiny amount compared to the millions of carats of diamonds consumed per year.

Crater of Diamonds is a dig-for-fee operation maintained by the State of Arkansas. The diamonds there are hosted in a lamproite breccia tuff and its overlying soil. Collectors pay a fee of a few dollars per day to prospect and can keep any diamonds that they find. This is the only diamond mine in the world that is open to the public. It has yielded a few significant finds: 1) the “Strawn-Wagner Diamond” – found at the Park as a 3.03 carat rough stone, it was cut to yield a 1.09 carat, “round brilliant” shape stone which received a perfect grading of 0/0/0 and stands as the most perfect diamond the American Gem Society has ever certified. 2) The “Uncle Sam” diamond, a 40.23 carat white diamond is the largest diamond ever found in North America. 

At present, there are no commercial diamond mines operating in the United States. The Kelsey Lake Mine near the Colorado-Wyoming border was closed in April 2002. Estimated resources of the Kelsey Lake Mine at closure were about 17 million tons – containing approximately 4 carats of diamonds per 100 metric tons. About 50-65% of the diamonds produced at Kelsey Lake Mine were gem quality and almost one third of the gems produced were over one carat in size. The two most valuable stones reported to have been from the Kelsey Lake Mine were valued at $89,000 and $300,000.

There is good potential for commercial diamond production in the United States. Multiple diamond discoveries in Canada have prospectors looking at comparable areas in Alaska andMinnesota. More importantly, the Wyoming Geological Survey believes that a $1 billion diamond industry could develop in that state. Wyoming has comparable conditions to the Canadian deposits and hundreds of kimberlite pipes are believed to exist. Twenty diamondiferous pipes have been discovered so far but assessment results have not been released to the public. 

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Diamond Mines of North America
The oldest and most famous diamond mine in North America is the Crater of Diamonds which is just south of Murfreesboro, Arkansas.  Diamonds were first suspected in the area and in 1889, state geologist John Branner gave the area a thorough surface search and didn’t find anything.  Seventeen years later, diamonds were found after John Wesley Huddleston bought the land to farm.  He was feeding his cattle one day and noticed two small stones in the bottom of the bucket.  After taking the stones to town to show the bank president, it was decided they would be forwarded on a Little Rock jeweler.  The jeweler then sent them to Tiffany’s in New York and both stones were certified as gem quality.  One was graded a 3.0 carat, white in color and the other was graded a 1.5 carat and yellow in color.  Upon his discovery of diamonds, Huddleston sold his property to some men from Little Rock for $36,000. (Crater of Diamonds State Park)
Throughout the 1900’s, the diamond bearing property passed from owner to owner.  It was commercially mined shortly after Huddleston sold it.  In 1949, it was first opened to the public by the owners at the time.  This continued until 1969 when General Earth Minerals of Dallas bought the property.  They never commercially mined the site, but kept it open to the public as a tourist attraction.  In 1972, the property was sold to the State of Arkansas to be used as a state park.  It still remains a state park and today you can dig for diamonds and keep what you find for $5.00.  The chances of finding a diamond are very small.  On the average, two diamonds are found each day.  The best time to look for diamonds is after a heavy rain.  Occasionally there are a few big diamond finds.  The Uncle Sam was found in 1924 and is 40.24 carats.  It is currently the largest diamond found in North America.  The next largest diamond found is the Star of Murfreesboro found in 1964 at 34.25 carats and then the Searcy diamond was found in 1926 and is 27.21 carats.  The interesting thing about the Searcy diamond is that it was found near Searcy, Arkansas, 175 miles from Murfreesboro, Arkansas. (Crater of Diamonds State Park)

The Searcy Diamond.  Image taken from Love Story┬«.

Diamonds have been recently mined in other parts of North America.  In 1996, the State Line Kimberlite District, found near the Colorado – Wyoming border started production of diamond mining.  It is the only operating diamond mine in the United States at this time.  There are also a number of places throughout Canada, mainly in the Northwest Territories where diamond mining is taking place.  Several companies including DeBeers are currently exploring this area for possible diamond mining.