28 GEMS AND PRECIOUS STONES IN THE
ley
and Cherokee Mining Company, in cleaning up the sluices. One of these
was described as large and straw-colored, while others were smaller,
but very pure. Various stones, white, yellow and pink, have from time
to time been reported, and some have been cut and set. A fine crystal
was presented to the State Museum by Mr. Williams, Superintendent of
the Spring Valley Mining Company. Two others, found at the same place
in the summer of 1881, by Lucinda Voght, were shown by the present
writer before the New York Academy of Sciences in 1886. Professor
Silliman made the concentrations from the sluices of these Cherokee
mines the subject of a minute investigation, the results of which were
published in two papers.1 In the first he describes his
treatment of the material, both chemical and mechanical ; and in the
second he gives additional particulars, with results. He finds here the
following association of interesting minerals; light-colored zircons,
crystals of topaz, fragments of quartz, rutile, epidote, pyrite, and
limonite, with some platinum, iridium, iridosmine, and gold, and a
large quantity of black grains, which are proved by the magnet to
consist about equally of chro-mite and titanite. At first he could find
but little of the platinum and iridosmine, but this was due, as above
stated, to the force of the hydraulic streams, which sweep away all
small particles that do not amalgamate. Mr. Hanks adds that platinum
minerals have been found rather abundantly in Butte County. At St.
Clair Flat, near Pentz, they were found in quantity in the early days
of placer-mining. They are found, also, at the Corbier Mine, near
Ma-galia (Dogtown). In 1861, a diamond was found one and a half miles
northwest of Yankee Hill, Butte County, in cleaning up a placer-mine.
The stone was taken from the sluice with the gold, and sold to M. H.
Wells, to whom I am indebted for this information. Mr. Wells presented
the gem to John Bidwell of Chico, who had it cut in Boston. It weighed
1-1/2 carats (4*75 grains). Mr. Bidwell gave the diamond to his
wife, who now wears it in a ring. This was the only diamond found in
this locality. In all the northern counties of California, drained by
the Trinity River, in the vicinity of Coos Bay, in Oregon, and on the
banks
1
See Mineralogical Notes on Utah, California, and Nevada, in The Eng.
and Min. J., Vol. 17, p. 148, March II, 1873, and the Am. J. Sci. III.,
Vol. 6, p. 127, Aug., 1873.
