THE LEOPARDITE (QUARTZ PORPHYRY) OF NORTH 



CAROLINA.^ 



INTRODUCTORY STATEMENT. 



While engaged, during the past summer, in. a study of the gran- 

 ites of North Carohna for the State Survey, opportunity offered for 

 examination in the field of the well-known and interesting rock 

 called "leopardite," which occurs near Charlotte in Mecklenburg 

 county. Knowledge of the occurrence of this rock in the state 

 dates back many years, and brief descriptions of it have been pub- 

 lished from time to time by different writers, as noted below in the 

 appended references. 



In 1853 Dr. Hunter^ briefly described, megascopically, the general 

 appearance, including locality, of the leopardite found near Char- 

 lotte, Mecklenburg county, North Carolina. He says: "It is noticed 

 by Professor Shepard, under the head of feldspar, as the leopard 

 stone of Charlotte, North Carolina." Professor Shepard regarded 

 it as composed of compact feldspar and quartz spotted by the oxides 

 of iron and manganese. Hunter suggested the propriety of retain- 

 ing the name "leopardite," for the reason that it is quite charac- 

 teristic of a rather unique rock. In the same paper the author 

 refers to a second locality in Lincoln county. North Carolina, where 

 leopardite had recently been found. Concerning the character of 

 the rock in Lincoln county, he says: "The pervading stripes are, 

 however, generally finer; and when broken diagonally, it presents 

 a handsome arborescent appearance." 



In 1862 Dr. F. A. Genth^ described the leopardite occurring near 

 Charlotte as a true porphyry, and gave some general results of a 

 microscopical examination of thin sections of the rock, including a 

 chemical analysis. Still a third locality in North Carohna where 



' Published by permission of the state geologist of North Carolina. 



^ C. L. Hunter, "Notices of the Rarer Minerals and New Localities in Western 

 North CsLTohna.," American Journal of Science., Vol. XV (1853, 2d ser.), p. 377. 



3 F. A. Genth, " Contributions to Mineralogy," ibid., Vol. XXXIII (1862, 2d ser.), 

 pp. 197, 198. 



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