Monday, June 27, 2005

diamond mining in the USA

From Wikipedia, the free encyclopedia
Description
The Crater of Diamonds State Park is an 888 acre (3.6 km²) Arkansas State Park situated over an eroded volcanic pipe. The park is open to the public and, for a small fee, rockhounds and tourists can dig for diamonds and other gemstones. Park visitors find more than 600 diamonds each year of all colors and grades. Over 24,000 diamonds have been found in the crater since it became a state park. Visitors may keep any gemstone they find regardless of its value.
In addition to diamonds, visitors may find semi-precious gems such as amethyst, agate, and jasper or approximately 40 other minerals and rocks such as quartz, barite, and calcite.
The crater itself is a 35 acre (142,000 m&sup2) gravelly open field that is periodically plowed to bring the diamonds and other gemstones to the surface. The remainder of the park consists of a visitor's center, interpretive center, campground, and picnic area. A 1.3 mile (2 km) walking trail along the Little Missouri River is available for hikers.
Murfreesboro is located just south of Hot Springs, Arkansas, the location of Hot Springs National Park. The park is open year round but experienced diamond hunters prefer hunting in the spring when rains wash dirt off of the gemstones and make them easier to spot.
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History
The first diamond was found at Murfreesboro in 1906 by John Huddleston who owned the property. Several unsuccessful attempts at commercial exploitation of the site have failed.
Soon after the original diamond was found and a "diamond rush" turned Murfreesboro into a boomtown for a time. Hotels in Murfreesboro are said to have turned away 10,000 people in a year's time. These refugees formed a tent city near the mine which was named "Kimberly" in hopeful honor of the famous Kimberly Diamond Mine in South Africa.
From 1952 to 1972 the crater was a privately owned tourist attraction. In 1972 the State of Arkansas purchased the crater and converted it into a unique state park.
Due to the uniqueness of the park, the diamond has come to be associated with the State of Arkansas. The diamond shape on the flag of Arkansas represents this association. The Arkansas State Quarter released in 2003 bears a diamond on its face and the logo of Arkansas State University incorporates a multi-faceted diamond.
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Geology
The Crater of Diamonds is a 95 million-year-old volcano that has eroded to ground level.
In ancient times all of Arkansas was under water except for the Ouachita Mountains, which were created by the continental plate riding up over the oceanic plate. About 100 million years ago, these plates began to stabilize. The last movements of the plates caused cracking in the earth's crust, which allowed molten material to rise to the surface. The heat and pressure during this event were exactly right for the carbon atoms to bond and form diamonds.
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Diamond-hunting techniques
Diamond hunters at the park use a variety of techniques to locate the gemstones. Some sit and observe the topsoil from a distance waiting for sunlight to reflect off of a diamond.
Pavilions with sluice beds are provided within the crater and hunters gather buckets of the gravelly soil and sort through them by hand while washing. Others sift the soil through wire mesh screens that are provided.
The park staff weigh and categorize the gemstones and minerals found for park visitors free of charge.
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Diamonds found
The largest diamond found at the crater is also the largest diamond ever unearthed in the United States, the 40.23 carat (8.046 g) Uncle Sam diamond. Other large diamonds found are Star of Murfreesboro at 34.25 carats (6.85 g), the 16.37 carat (3.274 g) Amarillo Starlight, and the Star of Arkansas at 15.33 carats (307 mg).
The 3.03 carat (606 mg)Strawn-Wagner Diamond has been cut to a 1.09 carat (218 mg) gem that has been graded as "D" flawless o/o/o which is the highest grade that a diamond can receive.
Retrieved from "http://en.wikipedia.org/wiki/Crater_of_Diamonds"
Categories: Arkansas state parksFrom Wikipedia, the free encyclopedia