Origin of name
The "Uncle Sam" diamond is the largest diamond ever found
in the United States, weighing 40.23 carats and discovered in 1924, by
Wesley Oley Basham in the Prairie Creek pipe mine, which later came to be
known as the Crater of Diamonds Park, situated in Arkansas. The diamond gets
its name from the nick name of the founder W.O. Basham, who was fondly
referred to as Uncle Sam by friends and associates.
Characteristics of the
diamond
The diamond is a 12.42-carat, emerald-cut stone with an
unknown color and clarity grade. The website of the Crater of Diamonds State
Park describes the diamond as a white diamond with a pink cast weighing
40.23 carats. The clarity of the diamond appears to be exceptional
from the photographs of the diamond.
The slight pink tone of the diamond may be caused by
slight plastic distortions in the crystal structure during its formation in
the earth's mantle or subsequent rise to the earth's surface. The
plastically deformed areas of the crystal change the absorption spectrum of
the stone imparting the pink color. Thus the "Uncle Sam" diamond is most
probably a Type IIa diamond, free of nitrogen and other impurities, but the
color being caused by plastic deformation of the crystal.
History
The rough diamond weighing 40.23 carats was discovered in
1924 in the Prairie Creek Pipe mine at Arkansas, by a workman of the
Arkansas Diamond Company, by the name of Wesley Oley Basham, whose nick name
was Uncle Sam. The white rough diamond became the largest diamond ever
discovered in the United States, and still holds that record.
The rough diamond was said to have been cut twice, and on
the second occasion transformed into a perfect emerald-cut diamond weighing
12.42 carats. In 1971, the Uncle Sam diamond was reported to have been sold
to an anonymous buyer for $ 150,000.
The Crater of Diamonds State park, located on State
Highway 301, in Pike Country, southwest Arkansas, near Murfreesboro, is the
only diamond mine in the world open to the public, where visitors are free
to search for diamonds, and keep what they find. In other words the park is
operating a "finders are keepers policy", a unique policy that has never
been tried out before in any part of the world. This unique approach had
proved to be a tremendous success, attracting over 60,000 visitors to the
park every year, among whom the lucky ones discover on an average about 600
diamonds every year. This works out to an average of two diamonds each day.
Geology of the Crater of
Diamonds State Park
The search area of the Crater of Diamonds State Park is a
36½ acre site, which is believed to be the eroded
surface of a gem-bearing volcanic pipe known as the Prairie Creek Kimberlite
pipe. These diamonds were formed millions or perhaps billions of years ago
deep inside the earth's crust about 200 to 300 Km below the surface of the
earth. The diamonds were subsequently brought to the surface of the earth by
a violent volcanic eruption, estimated to have taken place about 100 million
years ago. Test drilling at the crater has shown that the
diamond bearing reserve or pipe is shaped like a martini glass.
Kimberlites which are a type of
igneous rock are mica Peridotites that are found in pipes. They are rare
occurrences in the cratonic (stable) areas of the earth's crust. The
stable interiors of South Africa and Siberia have wide spread occurrences,
but these pipes are also found in north America, Australia, Brazil and
India. Not all Kimberlites contain diamonds. When diamonds do occur they
constitute less than one part per million of the rock.
The diamonds found in the Crater of
Diamonds site are generally less than one carat in size. Most of them are
about the size of a match head or even smaller. The diamonds exist in
different colors, however, the three most common colors found are white,
brown and yellow, in that order. Diamonds of significantly larger sizes
ranging from 2 to 40 carats have also been discovered, but their occurrence
is rare. Diamonds found at the crater are typically smooth well rounded.
They have a metallic luster and are generally translucent, i. e. light
passes through them but you cannot see the other side.
Besides diamonds a range of other
minerals are also found in this site such as quartz, amethyst, garnet,
peridot, agate, jasper, calcite, barite. In all about 40 different
rocks and minerals have been found in the site of the crater.
History of
the discovery of diamonds in the park
Diamonds were first discovered in the area in 1906, by
John Wesley Huddleston who bought a farm on the site. But it is reported
that two geologists had studied the site before 1906 with a view of
identifying potential diamond-bearing sites, but could not find any
diamonds. On August 8, 1906, while Huddleston was spreading rock salt on his
hog farm, he observed some shiny specks in the dirt around. His curiosity
aroused, Huddleston decided to probe the area that drew his attention, and
retrieved two shining pebbles from the dirt. Having refused an offer of 50
cents for the two stones from a local bank cashier, Huddleston dispatched
the two stones to a gem expert in New York City, who confirmed that the two
stones indeed were diamonds. One stone was a 3.0-carat white diamond, while
the other was a 1.5-carat yellow diamond.
News of the discovery of diamonds by Huddleston sparked a
diamond rush in Pike country. The farm next to Huddleston's owned by Millard
M. Mauney was also situated in the same gem-bearing crater. Diamond
prospectors and fortune hunters rushed to the area, and within a short time
the little town of Murfreesboro, assumed a boomtown atmosphere reminiscent
of the Kimberley township that developed in the cape region of South Africa
during the South African diamond rush in the late 19th century. Huddleston
sold his farm to a Diamond Mining Company for $ 36,000, and the public were
prohibited from mining in this area. Eventually the entire land covered by
the crater became the property of two rival diamond mining companies, the
Arkansas Diamond Mining Company and the Ozark Diamond Mines Corporation. It
was during this period in 1924, that the largest diamond ever discovered in
the United States, was found by a worker of the Arkansas Diamond Mining
Company, which was subsequently named the "Uncle Sam" diamond. Over the next
four decades the two companies engaged in sporadic mining activity, but
operated under severe financial constraints, compounded by poor management,
lawsuits and sabotage. Moreover the output of the mine was not sufficient to
sustain the operations of the mine and to further expand mining operations.
Thus the continued operation of the mine was not economical, and operations
ceased at the mine by early 1950s.
Development of the site
as a tourist attraction
In 1952 the owners of the rival companies formed a
partnership, not for further exploration of the mine, which they knew very
well was not worthwhile pursuing, but to develop the site as a tourist
attraction. They adopted the novel suggestion that the mine area be opened
to the public to look for diamonds after paying a nominal fee, and keep what
they find. The site was called the "Crater of Diamonds". A museum, gift shop
and restaurant were also built and the site was promoted aggressively as a
tourist attraction. The project turned out to be a modest success and
several diamonds of significant sizes were discovered during this period.
They are the 15.33-carat "Star of Arkansas" diamond discovered in 1956, that
sparked a second diamond fever. Other diamonds include the 6.42-carat Gary
Moore diamond discovered in 1960, and the 34.25-carat "Star of Murfreesboro"
discovered in 1964.
In 1972 the Crater of Diamonds was purchased by the State
of Arkansas, and converted into the Crater of Diamonds State Park. The new
state administration of the park continued with the open policy of allowing
the public to scout for diamonds for a fee, and keeping the find. Facilities
provided for visitors were tremendously improved, and today the park has
become one of the leading tourist attractions not only in the state but the
entire country. Some of the facilities provided for visitors include camp
sites, picnic sites, a cafe, standard pavilion that includes rest rooms,
laundry, and gift shops, hiking trails, and interpretive programs for park
visitors, and an aquatic play ground called the Diamond Springs. The parks
interpretive programs and exhibits explain the site's geology and history
and offer tips on recognizing diamonds in the rough. Diamond mining tools
are available for rent or purchase. The Diamond Discovery Center provides
free identification and certification of diamonds and minerals discovered.
Today the visitor turnout at the park is over 60,000
annually. Over 600 diamonds are discovered annually, which works out to an
average of two diamonds per day. Since the discovery of diamonds in the area
in 1906, over 70,000 diamonds have been unearthed, and since the
establishment of the State owned park in 1972, over 25,000 diamonds have
been discovered in the park. The largest diamond discovered since the crater
became an Arkansas state park in 1972, was the 16.37-carat white diamond the
"Amarillo Starlight" found in 1975 by W. W. Johnson, of Amarillo, Texas.
About 15 other diamonds ranging in size from 3 carats to 9 carats, have also
been discovered during this period.
Attempts to start
commercial mining at the site
In early 1990s Governor Bill Clinton of Arkansas signed a
bill to authorize a lease for commercial exploration and mining at the park.
A consortium of four mining companies undertook a preliminary exploratory
survey to look into the possibilities of starting a full-scale deep mining
operation. However, by 1994 it was clear that the returns from this
exploratory operation were not encouraging, to make a full-scale mining
operation viable. Consequently the companies decided to withdraw from the
project. Further studies conducted in 1996, confirmed the results of the
previous studies, and it appears that the Crater of Diamonds State Park is
destined to maintain its status quo as a popular diamond "hunting" ground
with all the thrill and adventure associated with it, and may continue to
maintain its foremost position as one of the most popular tourist
attractions in the country, into the foreseeable future.
