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PRECIOUS STONES. 683
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large
number of rounded pebbles of quartz, but no other of the associated
minerals of the diamond; and as the entire district consists of glacial
drift coming from the north, a diamond bed is not likely to exist in
the immediate vicinity, but is rather to be looked for in the direction
from which the drift came.
The
diamond is a rhombic dodecahedron, deeply pitted with circular,
elongated, reniform markings. In color it is slightly grayish-green.
But it is one of those diamonds in which the color is likely to be
superficial, and it would probably cut into a white gem. Its weight is
3-14/16 carats. This is the second authentic occurrence of diamond in
Wisconsin, the other occurrence being at Plum Creek, Pearce county, of
three small stones, the largest of which weighed f | carat, see the
last report (p. 759). A 16-carat diamond was reported to have been
found, also in glacial drift, at Waukesha, Wisconsin, in 1884. Some
litigation resulted from its finding, and considerable doubt was
expressed at the time as to the genuineness of the discovery.
A
small elongated crystal 7 mm. long and 4 mm. in diameter, weighing
three-fourths of a carat and of a bright, light canary color, with
polished surfaces, was found in the vicinity of Kings Mountain, North
Carolina, during the summer of 1893. Mr. H. S. Durden, of the
California State Mining Bureau, reports that two small diamonds were
obtained in 1892 and 1893; at Cherokee, Butte county, California. One
weighed 2 carats.
The
London Mining Journal of May 6,1893, states that important discoveries
of diamonds have been made in the Landak district of Borneo. Landak is
about three days by steamer from Singapore, and the district has been
declared by experts to be not only gem-bearing but auriferous. A large
number of diamonds have been taken from the beds of streams. Under
ordinary circumstance this would require dredging or diving, but at an
interval of every five or six years the streams become so abnormally
dry and shallow that the beds can be reached without difficulty.
Diamonds in meteorites.—The
discovery of diamonds in the Canyon Diablo meteoric iron was first
announced by Dr. A. E. Foote in the American Journal of Science for
July, 1891 (Vol. xlii, pp.
413-417). Diamonds have previously been noted in the Novy Urej Russian
meteoric stone by Latchinoff and Jerofeieff, and in the Arva, Hungary,
meteoric iron by B.Weinschenck. On cutting the Canyon Diablo meteorite
it showed extraordinary hardness, a day and a half being consumed and
chisels destroyed in the process of removing a section. In the cutting,
the chisels had fortunately gone through a group of small cavities,
which on examination were found to contain hard particles that cut
through polished corundum easily, while the emery wheel used to polish
the surface was ruined. The grains exposed were small and black, and
Prof. Geo. A. Koenig pronounced them diamonds because of their hardness
and their indifference to chemical reagents. The
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