Note on the Occurrence of Sapphires and Rubies in sitû with Corundum, at the Culsagee Corundum-mine, Macon County, North Carolina

Abstract

The oriental ruby and sapphire are, mineralogically considered, merely coloured crystals of corundum, which mineral species has been shown by chemical analysis to consist of the earth alumina in a crystallized state and nearly pure condition. Where these gems have been met with, they appear almost always, if not invariably, to have been discovered in the beds of rivers as waterworn pebbles; and although the existence of corundum in small quantities in granular limestone in Asia Minor and the United States has long been known, any thing like a deposit of this mineral in sitû , sufficiently abundant for commercial exploration, appears to have been altogether unknown, until the author's attention was directed to the occurrence of numerous fragments of corundum on the surface and in the river-beds of Macon County, North Carolina, which encouraged him to make a minute examination of this district, and resulted in the discovery, in the summer of 1871, of the deposits of corundum now known as the Culsagee Corundum Mine. The locality of this mine is a hill, situated about nine miles east of Franklin, the principal town of Macon County, the summit of which is some 400 feet above the valley and about 2500 feet above the level of the sea; geologically it is a boss of serpentine protruded through the surrounding granite.