History and Property of Jade

JADE is a verdant mineral known to man for ages, and used for personal ornaments, weapons, implements, art objects, and applied to interior decoration. The word emerald, so frequently appearing in ancient writings, is believed to have sometimes meant jade-an opaque to translucent mineral--and unlike the emerald in anything, excepting a slight resemblance in colour. The word "jade" is now a generic term applied to various mineral substances, as chloro-melanite, or jadeite, nephrite, saussurite, pseudo-nephrite; these minerals are characterised by toughness, compactness of texture, and a colour range from cream white to dark green and nearly black. Although appearing in the trade in precious stones and jewelry, in the art objects of every land, and although extensively imitated--sometimes in a fashion, however, that could deceive no one--"jade" is nowhere prized and appreciated so much as in the Chinese Empire; and wherever on the globe adventurous Chinese roam or locate it is always found as one of their most cherished possessions. Properly the term "jade" includes but two minerals; nephrite and jadeite. Nephrite is Nephrus amorphous of the order Chalicinea, according to Dana's system of mineralogy. The name is from a Greek word meaning a kidney; the ancient Greeks believing this mineral to possess the virtue of a specific remedy for all diseases of the kidneys, as, indeed, the Chinese believe now, and have for centuries. Jade is massive, of fine granular or impalpable substance; hardness, 6.5; specific gravity, 2.96 to 3.1; lustre, vitreous; streak, white; colour, leek-green, passing into blue, grey, and white; translucent to sub-translucent; fracture, coarse and splintery. An average specimen contains silica, 50; magnesia, 31; alumina, 10; oxide of iron, 5.5; and nearly three per cent. of water, with a tinge of chrome oxide. Jade is infusible before the blowpipe, but becomes white; with borax it forms clear glass.

Jadeite is a tough, fibrous foliated, to closely compact, mineral, grouped with the pyroxenes; hardness, 6.5 to 7; specific gravity, 3.33 to 3.35. Jadeite will fuse readily before the blowpipe to a transparent glass containing bubbles or blisters. A variety that is dark green verging on black is termed chloromelanite. Weapons and ornaments carved in jadeite in prehistoric times are found on every continent. But few of the localities from whence the mineral came that supplied raw material for these unnamed artisans and artists, are known; the most important is in the vicinity of Mogoung in Upper Burma, where it occurs in boulders embedded in a reddish-yellow clay in river valleys. The jadeite miners crack the boulders by heating, and the pieces found of merchantable quality are either sawed into the required shapes by slender steel saws, kept tense by bamboo bows, or sold as found to traders who come in caravans from China. The mineral here found is thus distributed throughout the Chinese Empire. Jadeite of milk-white colour is most highly prized and that with bright green spots is next in favour. Dr. Max Bauer states that he saw a piece of less than three cubic feet which sold for $50,000.

Nephrite occurs in gneiss and amphibole schists in the Karakash Valley in the Kuen Lun Mountains, Turkestan, and this is now an important source of supply; these mines have been worked for more than two thousand years. Nephrite is found in eastern Siberia, Silesia, Germany, and in New Zealand. Both nephrite and jadeite, carved into weapons and ornaments, have been found in all the Americas; the occurrence of nephrite in Alaska has been well established, and it is a possibility that much of the carved material found far south of Alaska originated there.