363 



[Genth. 



were found in the soil, shows a gradual change into several other min- 

 erals. The species which have been observed at this locality are dia- 

 spore, gibbsite (Seal*), damourite, margarite, soda-margarite, euphyllite, 

 zoisite, tourmaline, chlorite, lesleyite and pattersonite. 



About one mile from Unionville on the road to Kennett Square, corun- 

 dum crystals are found imbedded in granular albite, together with euphyl- 

 lite and tourmaline ; it is also ascociated with black spinel, chlorite, talc, 

 actinolite, etc. 



Of the occurrence of corundum in Virginia, I have only one indication 

 in the shape of a piece of a pebble from the neighborhood of Staunton, 

 Augusta County, which princijially consists, as shown by a qualitative 

 analysis, of chloritoid with minute particles of corundum disseminated 

 through it and a mass of damourite attached to, or passing in small 

 seams through the chloritoid. 



By far the most numerous localities of corundum, and many of them 

 of great scientific interest, are found in North Carolina. The most 

 Eastern occurrence which appear to belong to this formation, is on the 

 lands of the Widow McChristian near Friendship, in Guilford County, 

 and forms part of the great titaniferous iron ore belt of that State. 



The corundum, of which only some surface specimens have been found, 

 is a true emery, consisting of granular corundum, mechanically mixed 

 with magnetic iron. It is associated with a chloritic mineral, generally 

 changed into a'white micaceous one by weathering, ilmenite and .small 

 quantities of chromite. Two samples gave me as follows : 



Corundum = 52.24 — 44.86 



Magnetite =42.77 — 46.29 



Silicates, etc = 4.99 — 8.85 



The whole bed lies in granitic rocks and there is no sign of serpentine 

 or chrysolite in the neighborhood ; the presence of chromite, however, 

 and of the chlorites, closely resembling those of the serpentine range, 

 makes it probable that the belt belongs to the latter. 



Science is much indebted to Rev. C. D. Smith, to whom the credit is 

 due, for the discovery of the corundum belt which stretches with occa- 

 sional interruptions in a southwesterly direction from Madison County, 

 North Carolina, through Georgia into Tallapoosa County, Alabama, a 

 distance of at least 250 miles. Of this, C. U. Shepardf gave, a short 

 time ago, an elaborate description. The first large mass was found in 

 1847, on the French Broad River, three miles below Marshall in Madison 

 (then Buncomhe) County. It was of a dark-blue color and was associ- 

 ated with chlorite and margarite. The bed from which this and several 

 smaller masses occurring in loose boulders have come, has never been 

 found; but judging by the associated minerals there can be no doubt 

 that it came from the great chrysolitic belt. I believe that I was the first 



* T. F. Seal— Sill. Journ. [2] XI. 237. 



t C. U. Shepard— Sill. Journ. [3] IV, 109 to 114 and 175 to ISO. 



