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This is a rock, occurring in massive form, of which various varieties are worked and marketed under different names. The serpentine used in England is chiefly that which is found in Cornwall. Altogether, this material has not much to commend itself although its natural markings generally show up well when 1 the stone is polished.

A. silicate of magnesium, formed generally by the alteration of olivine-bearing material, it is usually oil green in color, quite opaque, and frequently mottled. Hardness varies from 2 1/2 to 4, specific gravity is 2.5, and the refractive index is approximately  1.57

tricts. The Lizard in Cornwall is a noted locality for this mineral, and here it is fashioned into a number of attractive objects, such as vases and ash trays. The turning and polishing are carried out with a simple lathe, and tempered steel saws are used in the cut­ting. Cameos have been made from this material, as have also larger ornamental pieces; it is even used as a building stone in some districts.

The black spots and veins often seen in serpentine are due to magnetic oxide of iron, which is usually present in some degree. Dull reds and browns, as well as the characteristic green, are com­mon. The low hardness will easily distinguish this material from other similarly colored minerals. Absence of large pieces of regu­lar shape make the quarrying of serpentine unsatisfactory. White veins of steatite are often included in the rough, which is also found as waterworn pebbles on the coast. These may be dark red or dark green in color, frequently marked or spotted black.

Another dark green serpentinous rock, called verdite, is some­times cut into beads and sold in the form of necklaces. This stone is often streaked with brown or greenish yellow. It is cut in Idar-Oberstein, being found in the Barberton district of the Trans­vaal, South Africa.

Bowenite is another variety of serpentine; apple green to a yellowish white in color, it sometimes resembles jadeite in appear­ance but is, of course, much softer. It occurs in India, U.S.A., New Zealand, and Afghanistan, and various ornaments and arti­cles, such as knife handles, are cut from it. It is seldom used in jewelry.

Other varieties of serpentine are williamsite, greenish in color and found in the U.S.A., antigorite, dark green and mined in Italy, and Connemara marble, massive green, mottled or veined with calcite. The last is popular in Ireland, where it is found in masses, and ornaments of all kinds are turned from it, including bead necklaces.