QUARTZ, Wuh-sih-shih-ying, CHIN., is nearly pm silica. It occurs both massive and in crystals of all sizes, and of a great variety of colours. Is much used in the bodiesof pottery, and in making enamel and glass. Quartz rock has been found the richest in metals of all the Indian rocks. At Callastry it contains lead ore mixed with silver • Nellore, copper • at Nagpur, manganese, lead ore, and copper. 'Micaceous iron ore is a very common product of this rock, and gold occurs in the western parts of the Peninsula of India. A quartz dyke, 5o to 100 feet in height, runs N. and S. to the W. of Hyderabad, in which crystals of amethyst occur.
Brown or Smoky Quartz occurs in fine crystals near Cairngorm in Aberdeenshire, and it is used for seals and ornaments when cut and polished.
Purple Quartz or Amethyst is found both crystal lized and massive. It is of every shade of purplish violet, and the colour in the perfect amethyst is pretty equal throughout the crystal or mass ; frequently, however, the summits of the crystals only are coloured. It Is used for ornaments. Amethysta of the first quality are fount! it, India, Ceylon, Persia, and Siberia.
.11esides these colours, there occur blue quartz (inderite), green, red (hyacinthine), and yellow (Scotch topaz, Itobeinian topaz), with the quirtzueo minerals and Inferior gems, agate, avanturine, bloodstone, flint, jasper, chrysoprase, and opal.
The Chinese name includes several qua:twee minerala: fluor spar, cairngorm, owninon quartz.
Beautiful regular crystals of quartz, called Kalabagli and Murree disunonda, are fount! itt the gypsum of Murree, Kalabagli, and Sanli in the Punjab. They are transpirent, milky, or red. They occur in the six-sided and dodecahedron form.
Hornstone and Cheri are varieties of compact quartz. Cavernous quartz is termed spongifonn quartz or swimming stone.
Green anti Quartzose Sandstone of Vellore were used formerly by farriers, but are now re placed by sills of corundtun and lac.
Yellow ,Quarizose Sandstone of Woodiagherry was used formerly for giving a first edge to swords, daggers, and implements ; hard, rough, and well suited for grindstones. See Precious Stone&