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GEMS AND PRECIOUS STONES.
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335
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ally fine purple and lilac-colored apatite crystals, chiefly suitable for mineral collections but occasionally cut for gems.
BEACH PEBBLES.
An unusual beach pebble found near Redondo, Cal., has been cut as an ornament by the Redondo Gem Co.1
This stone is shown by photograph to be about 6 inches by 5 inches
thick, consisting of a dark-colored matrix, thickly mottled by numerous
white to gray flower-like patches. The matrix of the stone is described
as brownish-black in color, with a large variety of flower patterns
discernible in the white markings, "such as the iris, morning glory,
daisy, and lily."
CATLINITE.
Dr.
Burt Ogburn, of Prescott, Ariz., submitted a specimen of cat-linite or
pipestone found near Jerome Junction. This material has a dull dark-red
color, with moderately smooth grain. On fractured surfaces the texture
looks somewhat gritty, but when carved with a knife it cuts evenly,
leaving a smooth surface quite similar to the catlinite of Minnesota.
So far the material has only been used locally for ornamental purposes.
ICELAND SPAR.
The
occurrence of Iceland spar in Sweet Grass County, Mont., was mentioned
in this report for 1913. Prof. J. P. Rowe, of the UniverÂsity of
Montana, at Missoula, has furnished further notes on this occurrence.
The deposit is located about 9 miles from Gray Cliff and has been
traced through the country for several miles. The Iceland spar occurs
in a fissure vein from 3 to 8 feet thick, cutting gneiss rock with a
northwest strike and almost vertical dip. All of the material mined
during 1914 was sold, and large excess orders were received. This
Iceland spar may be classed among the best grades of that material, and
some of the rhombs obtained measured over 2 inches thick, with perfect
transparency and without blemish. This grade is especially suitable for
optical work and for specimens. The smaller spar of equally good
quality is applied for various uses, and especially for standardizing
in chemical work. The present price of the Iceland spar varies from 50
cents to $4 a pound.
PRODUCTION.
The
total production of gems and precious stones in the United States in
1914, as reported to the Survey, amounted to $124,651. This is a large
decrease from the production reported for 1913, which amounted to
$319,454. The principal production of precious stones in the United
States consists of the semiprecious and ornamental stones, a large part
of which has been cut in Europe, especially in Germany, to which
country exports of such minerals have naturally decreased. An important
change during the year was the decrease in the production of Montana
sapphire, due to the fact that the largest placer mines were not
operated and that the mines of matrix deposits, all of which are owned
by an English company, were closed
1 Jewelers' Cireular-V.'eekly, July 15,1914.
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