Ch. 7: Quartz Group - Opal, Rock Crystals, Amethysts, Rose Quartz, Agate, etc.

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	118	GEMS AND PRECIOUS STONES IN THE

	is governed by their beauty, varying from $3 to $40 per ounce of quartz. The specific gravity of the mineral is first taken, after which the gold value of the quartz is ascertained by Price's table. The amount of this material sold in the rough for jewelers' purposes is variously estimated at from $40,000 to $50,000 a year, $1,000 to $2,000 worth being often purchased at one time. One lapidary at Oakland, Cal., where most of the cutting of this material is done, bought nearly $10,000 worth within a year, and a large jewelry firm in San Francisco, during the same time, purchased nearly $15,000 worth. In the selection of the quartz, great care is necessary. The stone used must be large enough to bear the rough treatment of the diamond-saw and the lap-wheel of the polisher. All of the rock quartz is friable, and some of it crumbles to pieces while undergoing these processes. The saw, catching in the gold in the slitting, prevents the cutting of large pieces, as the wafer-like slabs are apt to be broken by this resistance while being detached from the mass. For this reason, all the pieces set in cabinet work are small. Pieces 4 by 2 inches are quite rare, although fine pieces 4 inches square are at times seen. Rarely more than half of the rough material purchased finds its way into the market, owing to breakage while being trimmed into shape. The white gold quartz of California is mainly supplied from the counties of Butte, Calaveras, El Dorado, Mariposa, Nevada, Placer, Sierra, Tuolumne, and Yuba. The black gold quartz, a quite recent novelty, is found at the Sheep Ranch Mine, Calaveras County, and at Sutter Creek, Amador County. The so-called rose gold quartz is made by backing a translucent quartz with the desired shade of carmine paste, and forms an effective contrast to the opaque white and black gold quartz with which it is usually mounted. Single specimens for scarf-pins, rings, and sets of pins and ear-rings sell from $2 to $10 each. Exceptionally fine or curious pieces bring higher prices. It is within a few years that gold quartz has been utilized to any great extent in jewelry. At first the designs were usually simple and the mountings modest, but the demand has created a supply of elaborate designs, and at present the quartz is used in every conceivable form of jewelry, and in articles of personal adornment and decoration of almost unlimited

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