ZINC PRODUCTION The United States is the principal producer of both zinc ore and spelter. The Joplin area in Missouri has long been the principal mining region, but large depositS are worked in the Upper Mississippi region, Franklin Furnace (New Jersey) and, since the application of improved methods of zinc concentration, in the western States. Australia is next to the United States as a zinc producer, most of the ore being obtained from the Broken Hill district (New South Wales). Tasmania also has important deposits and occurrences are known in Australia.
In Canada, the most important deposits of the metal occur in British Columbia and Quebec, these two provinces sharing prac tically the whole of the Canadian production in the proportions of four-fifths and one-fifth respectively. The principal countries in Europe participating in the zinc industry are Germany, Italy, Poland and Spain. For many years Germany ranked second only to the United States. Her most important deposits were in Upper Silesia, which yielded about three-fourths of the total German production. Before the World War the European industry was almost wholly controlled by the German zinc convention.
In Italy the chief mines now worked are in Sardinia, though occurrences of ore are found in Lombardy, Piedmont and Tus cany. During the post-War period Poland produced more zinc ore than any other European country, her richest mines being situated in Silesia; her exports in 1923 amounted to 8o,000 long tons. In Spain the chief zinc-mining centres are in the provinces of Santander and Murcia. The ores of Santander are mainly calamine, while those of Murcia are principally blende and galena. Mention should be made of the zinc-ores mined in the United Kingdom. These are almost invariably blende associated with galena, and occur chiefly in North Wales, the north of England, the Isle of Man and at Dumfries in Scotland.
In the following table the production of zinc in the principal countries of the world is set out for the three years, 1918, 1923 and 1925.
C. Ball, "The Etheridge Mineral Field," Queens land Geological Survey, No. 245 (1915) ; J. C. Moulden, "Zinc; Its Production and Industrial Applications," Jour. Roy. Soc. Arts, vol. 64, PP. 495-513, 517-529 (1916) ; A. Stansfield, "Canadian Zinc Re sources," Canadian Mining Institute Bull. 52 (1916) ; W. L. Uglow, "Lead and Zinc Deposits in Ontario and in Eastern Canada," Rep. Ontario Bur. Mines, vol. 25, pt. 2 (1916) ; J. C. Brown, "Geology and ore deposits of the Bawdwin Mines," Records Geol. Surv. India, vol. 48 (1917) ; Zinc Ores, Imperial Institute Monographs on Mineral Resources (1917) ; A. M. Sen, "Notes on the Occurrence of Lead, Zinc and Antimony Ores in Mysore," Dept. Mines and Geology, Mysore State, pp. 9-20 (1917) ; T. E. Lones, Zinc and its Alloys (1919) W. Versfeld, "The Base Metal Resources of the Union of S. Dept. Mines and Industry of Union of S. Africa (1919). For full raphy see Imperial Mineral Resources Mineral Industry of the British Empire and Foreign Countries, 1913-20, PP. (1921). (N. M. P.) ZINCITE, a mineral consisting of zinc oxide (Zn0), crystal lizing in the hemimorphic-hemihedral class of the hexagonal system. Distinct crystals are of rare occurrence; they have the form of a hexagonal pyramid terminated at one end only by a basal plane. There is a perfect cleavage parallel to the basal plane, and usually the mineral is found as platy foliated masses. The blood-red colour and the orange-yellow streak are charac teristic The hardness is 4.5, sp.gr., 5.6. Some man ganese is usually present replacing zinc. It is known only from Sterling Hill and Franklin Furnace in Sussex county, N.J.