Ch. 3: Precious Gem stones in 1911

Ch. 3: Precious Gem stones in 1911 Page of 105 Ch. 3: Precious Gem stones in 1911 Text size:minus plus Restore normal size   Mail page  Print this page
1046
MINERAL RESOURCES.
in some quantity in Siskiyou County and Butte County, and some of it contains a few emerald-green spots. The green californite from Siskiyou County is not greatly different in color from jade used for earrings by the Chinese and is mottled with similar patches of green.
CHRYSOPRASE. CALIFORNIA.
In the description of the chrysoprase deposits of Tulare County, Cal., in this report for 1909, a prospect of the Himalaya Mining Co. near Lindsay was mentioned in connection with the notes on that company's mine, three-fourths of a mile north of town. This pros­pect was examined in 1911. It is in the top of a low hill about a mile S. 70° E. of Lindsay. The hill is about one-third of a mile long in a N. 25° W. direction. It rises about 60 feet above the plains at the ends and is lower in the middle. Several small prospect pits and trenches had been made, chiefly at the north end of the hill, but little gem chrysoprase was found. The occurrence is similar to that of the other deposits. Jaspery and cherty serpentine heavily stained with yellow and red iron oxides outcrops along each end of the hill in rough ledges and masses. Fine-grained diorite forms the west central portion of the hill. The jaspery serpentine is cut in many directions by seams and veinlets of chalcedony and fine-grained chai-cedonic quartz, ranging from paper thickness to 2 or 3 inches thick. In some of these veinlets there was a slight tint of green, but no chrysoprase was observed. Veinlets of greenish and yellowish-green opal are also plentiful through the jaspery serpentine.
The production of chrysoprase in 1911 came from the mine of the Himalaya Mining Co., 8 miles southeast of Porterville, and from some of the deposits on Venice Hill, 8 miles east of Visalia. Some high-grade gem material was obtained at each locality. A quantity of low-grade chrysoprase and some chrysopal are obtained during min­ing. These are generally shipped to Germany for cutting.
ARIZONA.
The occurrence of chrysoprase about 20 miles west of Mineral Park, in Mohave County, Ariz., was mentioned in this report for 1908. The deposits are owned by John L. Riggs and Walker Bros., of Chloride. The occurrence is quite different from the California localities. Speci­mens sent by Mr. Riggs were decomposed fine-grained rhyolite por­phyry with small quartz phenocrysts and perlitic volcanic glass country rock. Associated minerals of the chrysoprase were black flint, red and brown jasper, gray and white chalcedony, and quartz. Some of the specimens were brecciated and contained fragments of chrysoprase. So far high-grade gem material has not been found, but the brecciated matrix containing chrysoprase would furnish unusual and attractive gems for the tourist and souvenir trade. Large lumps of rather granular opaque chrysoprase have been found which could bo cut into small ornaments.
The so-called "blue chrysoprase," or copper-stained chalcedony, from the Keystone and Live Oak copper mines near Miami, Ariz., was described in this report for 1909. Very little of this material is now obtained from the mines, as the workings have been carried
Ch. 3: Precious Gem stones in 1911 Page of 105 Ch. 3: Precious Gem stones in 1911
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US Geol. Surv. 1911. Gemstones, Metals.
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