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Showing posts with label Kimberlite. Show all posts
Showing posts with label Kimberlite. Show all posts

Monday, June 29, 2009

Arkansas "Diamond"

A rough yellow Diamond from Arkansas
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The Arkansas Legislature designated the Diamond as the official state gem in 1967, along with the Quartz crystal as the state mineral and Bauxite as the state rock. Arkansas is one of the few places in North America, other than Canada, where diamonds are present and currently the only place in the world where tourists may hunt for them. The importance of diamonds in Arkansas history is also acknowledged on the State Flag and the Arkansas state commemorative quarter issued in 2003.
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Diamonds were discovered in Arkansas in 1906 near the mouth of Prairie Creek southeast of Murfreesboro, and later diamonds were reported from two small areas two miles northeast of the Prairie Creek pipe. The Crater of Diamonds volcanic pipe is part of a 95 million-year-old eroded volcano. The deeply sourced lamproite magma, from the upper mantle, brought the diamonds to the surface. The diamonds had crystallized in the cratonic root of the continent long before, and were sampled by the magma as it rose to the surface. This lamproite diamond source is unusual, as almost all diamonds are mined from kimberlite and from alluvial deposits of diamonds weathered from kimberlite. The only other prominent lamproite diamond source is the Argyle Diamond Mine in Australia. Although these discoveries in Arkansas created a modest local sensation, attempts to mine Arkansas diamonds commercially during the first half of the twentieth century were without sustained success. In the 1950s man-made diamonds suitable for industrial purposes were developed and sealed the fate on Arkansas' diamond mining prospects.
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The failed commercial mining operations became a tourist attraction after World War II. The State of Arkansas bought the volcanic pipe property and some surrounding acreage for $750,000, which became the Crater of Diamonds State Park in 1972. The lure of finding gem-quality stones has drawn a steady flow of visitors to this unique attraction: nearly 2.3 million guests visited the park from 1972 to 2005. To aid the visitors in finding diamonds and other gemstones, the park plows up the fields several times a year to bring new lamporite to the surface. Park visitors find more than 600 diamonds each year of all colors and grades. Over 25,000 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, Apaptite, Jasper, Garnet, Quartz, Baryte, Fluorite, Calcite and some 40 other minerals. In nearby Hot Springs are located several Quartz mines, also open to the public for digging.

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Thursday, November 20, 2008

Another Find at the Arkansas Diamond Fields !

It's happened again, another big find at Arkansas' Crater of Diamonds State Park in Murfreesboro. Rhonda Bankston from Baton Rouge, Louisiana, saw a segment about the park on The Travel Channel’s “The Best Places to Find Cash and Treasures.” So, she and a friend decided to head out to camp at the park and give diamond hunting there a try.
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On Sunday, around 11:00 a.m. on her second day of prospecting in the park’s 37 ½-acre search area, Bankston found a stunning, what appears to be flawless 2.09-carat white diamond as she was surface searching over the plowed field. The field is the eroded surface of the world’s eighth largest diamond-bearing deposit in surface area. She found the gem near a sign that marks the spot where the 40.23-carat Uncle Sam diamond, the largest diamond ever unearthed in the U.S., was found back in 1924. After her gem is appraised, Bankston will decide whether to keep the diamond or sell it. Shaped somewhat like, and about the size of, a tooth, her sparkling white diamond looks like a frosted ice cube.
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Crater of Diamonds State Park is the world’s only diamond-producing site open to the public. Diamonds come in all colors of the rainbow. The three most common colors found at the park are white, brown and yellow, in that order. The park staff provides free identification and certification of diamonds. Park interpretive programs and exhibits explain the site’s geology and history and offer tips on recognizing diamonds in the rough. In total, over 75,000 diamonds have been unearthed at Arkansas’s diamond site since the first diamonds found in 1906 by John Huddleston, the farmer who at that time owned the land, long before the site became an Arkansas state park. The largest diamond ever discovered in the United States was unearthed here in 1924 during an early mining operation. Named the Uncle Sam, this white diamond with a pink cast weighed 40.23 carats. Other semi-precious gems and minerals found at the Crater of Diamonds include amethyst, garnet, peridot, jasper, agate, calcite, barite and quartz. Over 40 different rocks and minerals are unearthed at the Crater making it a rock hound's delight.
A fairly nice .24 ct yellow Diamond found at the Arkansas Diamond Mines.
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Crater of Diamonds State Park is located two miles southeast of Murfreesboro. It is one of the 52 state parks administered by the State Parks Division of the Arkansas Department of Parks and Tourism.

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The above two rocks, when located, tell you that you may be in Diamond Fields. Lamproite, on the left, contains small Diamond flecks but when associated closely to deposites of Kimberlite, on the right, in the same field, chances of larger Diamond finds are possible. Both of the above pieces were acquired by this writer during a visit to the same Arkansas Diamond Fields as the newest find. Sadly no Diamonds were found during that visit.
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Parts of this article from announcement by KARK Chnl 4 News
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