186 NOTES ON THE CORUNDUM OF 



rapidly other localities were brought to light along a distance 

 of forty miles. 



The colors of the corundum as found along this zone of 

 outcrops are blue, gray, pink, ruby, and white. Sometimes it 

 has broad cleavage faces, and then again it occurs in hexagonal 

 prisms. One hexagonal prism weighed over three hundred 

 pounds. There is a difference in the cleavage and the associate 

 minerals at different localities. 



In the development in North Carolina the corundum occurs 

 in chrysolite or serpentine rocks, and outside of serpentine it 

 has not been found. These chrysolite rocks belong to a regular 

 system of dikes, which have been traversed for the distance 

 of about one hundred and ninety miles. This system of dikes 

 lies on the north-west side of the Blue Eidge, and has a strike 

 parallel to the main mass of the ridge, and has an average dis- 

 tance from the summit of the ridge of about ten miles. It 

 continues this strike to the head of the Little Tennessee Eiver, 

 say from Mitchell to Macon County, one hundred and thirty 

 miles. Here the ridge curves around the head of the Tennessee 

 and falls back about ten miles to the north-west. In conformity 

 with this elbow in the ridge the disturbing force shifts to the 

 north-west and re-appears at Buck's Creek, having relative 

 position to the Blue Eidge. 



The serpentine appears at intervals along this whole line 

 of one hundred and ninety miles. There is a corresponding 

 system of dikes traversing the southern slope of the Blue Eidge, 

 but not so regular and compact as the system on this north- 

 west side, nor are the outcrops so frequent. The main mass of 

 the ridge bears no evidence of having been disturbed at all, at 

 least none have been found. From Mitchell County to Macon 

 the serpentine is usually inclosed in a hard crystalline gneiss- 

 rock, which bears rose-colored garnets, kyanite, and pyrite. 

 After its shifting to the right it occurs in hornblendic beds and 

 gneiss. At Buck Creek and thence south-westward the horn- 

 blend beds assume very large proportions, and instead of com- 

 mon feldspar have in them albite, making an albitic syenite. 

 At Buck Creek (which is named Cullakenih) the chrysolite 

 covers an area of about three hundred and fifty acres. One or 

 two observers have fallen into the error of confounding the two 

 dike systems, whereas they have no connection whatever. 



