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Ch. 6: Quartz Amethyst

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CHRYSOPRASE.
293
the latter substance. This mineral is found in the serpen­tine of Silesia; also, in Siberia, and in the United States (in New Hampshire).
Chrysoprase is used in jewelry and for various ornamental purposes, such as breastpins, rings, bracelets, necklaces, seals, &c. ; and the larger masses are used for snuff-boxes, cane-heads, table-plates, &c. The cutting is pretty difficult, and the greatest care is required for finishing the same with facets, as it is easily fissured ; it is done on tin or lead plates with' emery, keeping the first constantly wet with water ; it is polished on a tin plate with rotten-stone, but the lapidary has always to be cautious not to let it become hot, as it easily splinters, and grows opaque and gray. The usual cut is the table or cabochon, with facets on the border ; in setting, a foil of green satin is often used for a back, but when pure and of good color, it is mounted à jour. Inferior specimens are painted on the back with a mixture of verdigris, white lead, and gum mastic, or with sap-green.
The Chrysoprase loses its color by wearing ; heat and sunlight likewise cause it to fade, and render it dark and cloudy ; but the color may be restored by keeping it in a wet or moist place, such as a cellar, in wet cotton or sponge, or even by dipping it in a solution of nitrate of nickel, which serves likewise to improve the inferior qualities.
Very fine imitations in paste may be made by mixing
The chrysoprase is subject to a great many faults, such as fissures, either natural or received in cutting ; oily whitish spots, pale gray flaws and stripes, and sometimes small grains of clay of reddish color, intermixed in the interior of the stone ; but when pure, the chrysoprase has always been
Ch. 6: Quartz Amethyst Page of 515 Ch. 6: Quartz Amethyst
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