Much of the nephrite used by the Chinese has been obtained from quarries in the Kuen-lun mountains, on the sides of the Kara-kash valley, in Turkestan. The mineral, generally of pale colour, occurs in nests and veins running through hornblende-schists and gneissose rocks, and it is notable that when first quarried it is comparatively soft. It appears to have a wide distribution in the mountains, and has been worked from very ancient times in Khotan. Nephrite is said to occur also in the Pamir region, and pebbles are found in the beds of many streams. In Turkestan, jade is known as _yashm_ or _yeshm_, a word which appears in Arabic as _yeshb_, perhaps cognate with [Greek: iaspis] or jasper. The "jasper" of the ancients may have included jade. Nephrite is said to have been discovered in 1891 in the Nan-shan mountains in the Chinese province of Kan-suh, where it is worked. The great centre of Chinese jade-working is at Peking, and formerly the industry was active at Su-chow Fu. Siberia has yielded very fine specimens of dark green nephrite, notably from the neighbourhood of the Alibert graphite mine, near Batugol, Lake Baikal. The jade seems to occur as a rock in part of the Sajan mountain system. New deposits in Siberia were opened up to supply material for the tomb of the tsar Alexander III. A gigantic monolith exists at the tomb of Tamerlane at Samarkand. The occurrence of the Siberian jade has been described by Professor L. von Jaczewski. Jade implements are widely distributed in Alaska and British Columbia, being found in Indian graves, in old shell-heaps and on the sites of deserted villages. Dr G. M. Dawson, arguing from the discovery of some boulders of jade in the Fraser river valley, held that they were not obtained by barter from Siberia, but were of native origin; and the locality was afterwards discovered by Lieut. G. M. Stoney. It is known as the Jade Mountains, and is situated north of Kowak river, about 150 miles from its mouth. The study of a large collection of jade implements by Professor F. W. Clarke and Dr G. P. Merrill proved that the Alaskan jade is true nephrite, not to be distinguished from that of New Zealand.