corundum, synthetic corundum.7, gems

A broad review of the international precious-stone industry during 1910, emphasizing diamond production, markets, cutting, and major new gem discoveries. Kunz criticizes misleading trade names and undisclosed artificial gems, discusses the growing use of platinum in jewelry, and notes strong demand for emerald, pearl, sapphire, and other colored stones. Diamond coverage is extensive, including De Beers, Premier, Voorspoed, the Vaal River diggings, German Southwest Africa, the Belgian Congo, Australia, Brazil, British Guiana, Canada, and the developing Arkansas field, together with production statistics and the diamond-cutting industries of Antwerp, Amsterdam, and Germany. Of particular gemological importance is the account of microscopic diamonds in chromite-bearing altered peridotite from British Columbia. Colored stones include the Burma Ruby Mines at Mogok, Montana sapphires, and an extraordinary 110.5-kg transparent aquamarine crystal from Minas Gerais, Brazil. Kunz also introduces the name morganite for the fine rose-colored beryl newly mined in Madagascar, describing its occurrence, properties, and association with tourmaline and kunzite. Further sections treat moldavite and tektites, tourmaline, peridot, jade and jadeite, Ceylon moonstone, Lightning Ridge black opal, Baltic amber, Whitby jet, and pearl fisheries in Bahrain, Ceylon, and the United States.