THE NONMETALLIC MINERALS. 227 



(Specimens Nos. 63102, 63103, 63104, 63105, 63106, U.S.N.M.), showthe 

 character of the ore as mined and the character of the wall or country 

 rock. 



The chief commercial sources of emery are those of Gumuch-dagh, 

 between Ephesus and the ancient Tralles; Kulah, and near the river 

 Hermes in Asia Minor, and the island of Naxos, whence it is quarried 

 and shipped from Smyrna, in part as ballast, to all parts of the world. 

 The only commercial source of importance in the United States, or 

 indeed, in North America, is Chester, Massachusetts, as above noted. 

 The island of Naxos is stated to have for several centuries furnished 

 almost exclusively the emery used in the arts, the material being 

 chiefly obtained from loose masses in the soil. The mining at Kulah 

 and Gumuch-dagh was begun about 1847 and at Nicaria in 1850. The 

 emery vein at Chester, Massachusetts, was discovered by Dr. H. S. 

 Lucas in 1863, and described by Dr. C. T. Jackson in 1864. 



In preparing for use the mineral, after being dug from the soil or 

 blasted from the parent ledge, is pulverized and bolted in various 

 grades, from the finest flour to a coarse sand (Specimens Nos. 59844 to 

 59864, U.S.N.M., inclusive). The commercial prices vary according 

 to grade from 3 to 10 cents a pound. At the end of the last century the 

 price of the Eastern emery is given at from $40 to $50 a ton. About 

 1835 an English monopoly controlled the right of mining and the price 

 rose in 1847 to as high as $140 a ton. 



The chief uses of emery and corundum, as is well known, are in the 

 form of powder by plate-glass manufacturers, lapidaries, and stone 

 workers; as emery paper, or in the form of solid disks made from the 

 crushed and bolted mineral and cement, known commercially as emery 

 wheels. The great toughness and superior cutting power of these 

 wheels renders them of service in grinding glass, metals, and other 

 hard substances, where the natural stone is quite inefficient. 



(See further under Grind and Whet Stones, p. 463.) 



BIBLIOGRAPHY OF CORUNDUM AND EMERY. 



JOHN DICKSON. Notes. 



American Journal of Science, III, 1821, pp. 4, 229. 



J. LAWRENCE SMITH. Memoir on Emery First part On the Geology and Miner- 

 alogy of Emery, from observations made in Asia Minor. 



American Journal of Science, X, 1850, p. 354. 



J. LAWRENCE SMITH. Memoir on Emery Second part On the Minerals associated 

 with Emery. 



American Journal of Science, XI, 1851, p. 53. 



WILLIAM P. BLAKE. Corundum in Crystallized Limestone at Vernon, Sussex County, 

 New Jersey. 



American Journal of Science, XIII, 1852, p. 116. 



CHARLES T. JACKSON. Discovery of Emery in Chester, Hampden County, Massa- 

 chusetts. 



Proceedings of the Boston Society of Natural History, X, 1864, p. 84. 

 American Journal of Science, XXXIX, 1865, p. 87. 



