APPENDIX 13. 
CORUNDUM AND ITS ASSOCIATED ROCKS. 
BY BEY. C. D. SMITH. 
I propose, in this paper, to discuss that rare and valuable mineral, 
Corundum. The discovery of it in the United States is of comparatively 
recent date. Its discovery and development in quantity sufficient to 
render the mining of it an object, and to give to it a commercial and 
economic value amongst the resources of North Carolina, is of very recent 
date. Its geological and lithological relations and character are matters 
of scientific interest, and claim for it a place in the official report for the 
State. The probable introduction of its use into the arts, and the con- 
sequent demand for it in quantity, will necessarily make it an important 
article in our resources. 
The geological formation to which the outcrops that bear Corundum 
belong, is of the Azoic time or age. The principal mass of the Blue 
Ridge, as it tends southwards from the Grandfather Mountain, is Granite 
and granitic Gneiss. These rocks are quite crystalline and have a large 
per cent, of Feldspar in their composition. They are the oldest rocks upon 
the continent, perhaps in the world, and are, in the proper sense of the 
term, primordial. The rocks, of which the main mass of this part of the 
Blue Ridge is composed, bear very little evidence of being disturbed 
since the upheaval. 
There is, however, a zone of gneissic rocks on the northwest side of 
the ridge, which has been much disturbed since the main mass was folded 
up. At this point, where the Corundum is found, this zone lies about ten 
miles from the summit of the Blue Ridge, though as it tends northeast- 
ward, it diverges further and further from the principal elevation until it 
crosses the French Broad Yalley, when, owing to the curvature of the 
ridge to the northward, it approaches nearer and nearer the main eleva- 
tion, and so passes directly into the angle, where the Blue Ridge and Iron 
Mountain separate. Along the entire length of this zone from Cane 
creek, in Mitchell county, to Choeestoee, in Union county, Georgia, and 
perhaps still further south, there is a system of dike fissures through 
which, at intervals, Chrysolite and Serpentine have been protruded. The 
