THE BOOK OF DIAMONDS
deposits
is generally confined to the regions of the Southern Appalachians, the
Great Lakes and the Coast and Sierra Nevada ranges of California and
Oregon.
Diamond
mining in the United States is so unimportant that it hardly deserves
any mention. As a matter of fact there is not a single diamond mine
operating in this country at present. Arkansas is the only state where
diamonds have been mined. At Murfreesboro, Pike County, Arkansas, in
1906, small diamonds were found in a ground somewhat resembling the
blue ground of Kimberley, South Africa. In 1925 diamonds were mined at
this place. It is estimated that the output of the Arkansas diamond
field from the time of its discovery in 1906 to 1912 was approximately
1,400 stones weighing 550 carats and valued at about $12,000. Some
diamonds that are found in Arkansas are so small that 50 of them would
be required to weigh one carat. The largest diamond found in Arkansas,
in 1924, weighed 40.23 carats. The American diamond industries— the
mines of Arkansas—were closed in 1929 which fixed an index of returns
within the economic activities of the United States, that is, these
Arkansas mines could not compete with the South African mines. They
have not reopened up to the present.
A
diamond was found while miners were searching for gold in the interior
of British Guiana. The average size of diamonds found in this place was
6.1 stones per carat. Quite a large number were found here. Diamonds
have been found also in the central part of Dutch Guiana. All of these
are alluvial deposits, apparently very shallow and sim-
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