92 Journal of the Mitchell Society ^August 



sioaal ruby were found, none of them produced a great amount 

 of material. A ruby deposit, however, was discovered in 1893, in 

 Cowee Valley, Macon County, North Carolina, that has produc- 

 ed some remarkably fine rubies equal in color and lustre to any 

 of the Burma stones. Although these ruby deposits have been 

 developed for a great many years, only a very small amount 

 of material obtained has thus far found its way on the m'arket. 



commercial minerals associated with pegmatite.^ 



Many of the minerals that were assigned to the author for 

 discussion are associated with pegmatite. The mining of some 

 of these has not proved profitable until some of the associated 

 minerals could be produced and marketed. From some of the 

 peginatitic dikes in the Southern States several minerals are 

 now being ^nined. Mica stands out prominently as the prin- 

 cipal mineral obtained from these dikes, with kaolin a close 

 second. The potash feldspars, which occur quite abundantly 

 in some localities, have only recently been mined on account 

 of their former distance from the railroad. 



These pegmatites are not all of the same origin, some being 

 true dikes of igneous origin and others having an aqueo-igiieous 

 origin. I shall not try to take up here any discussion regarding 

 the origin of the pegmatites. 



The three principal minerals of the pegmatitic dikes are 

 quartz, feldspar, and muscovite mica, and these probably con- 

 stitute about 95 to 99 per cent, of the dike. Besides these, 

 there are a large number of minerals that have been found in 

 these dikes, some occurring sparingly and others abundantly. 

 There is given below a list of those minerals that are known 

 'to have been found in the pegmatitic dikes of the Southern 

 States, and those which have been obtained in sufficient quanti- 

 ty to be of value commercially are marked with an asterisk. 



list of minerals found in the pegmatitic dikes of the 



southern states 



Actinolite 



Albite* (Feldspar) 



' N. C. Geol. Survey. Economic Paper 3, 1900 p. U. S. Geol. Survey Min. Res. 



