«enth.] ^OO [August 18, 



The analyses rave : 



100.02 — 100.11 —100.00 — 100.45—100.60 —99.36 



f. Another locality which furnishes flattened nodules of mica, with a 

 nucleus of corundum, is the Haskett mine in Macon county, N. C. They 

 are mostly small, rarely over 10""" in diameter, and contain a grayish- 

 white corundum, surrounded by a subfibrous or fine scaly mica. 



There are many other localities in which corundum altered into mica 

 have been observed since the publication of my paper, but the specimens 

 from them do not present any other than ordinary interest, I will there- 

 fore mention only a few localities : Franklin. Sussex county, N. J. (rare). 

 Hogback, Jackson county, N. C, Cheohee, S. C, and also corundum 

 from gravel beds, at the Placer mines at Gainesville, Ga., Brindetown 

 and elsewhere in Burke county, McDowell county, etc., N. C. 



4. Corundum, altered into Margarite. 



The change of corundum into potassium mica is far more common than 

 that into calcium mica or margarite. 



a. One of the first observed in this State was brought to our notice by 

 Prof B. Sillinian, in 1849, who published a description of tiiat, found near 

 Village Green (Am. Journ. of Sc. [2] viii, 378), of which he gives several 

 analyses by Mr. W. J. Craw. When I published my paper on corundum, 

 I did not notice this occurrence, as I had, at that time, not been able to ex- 

 amine any specimens. The corundum is of a dark brown color, showing 

 sometimes, especially when wet, beautiful reflections of a rich bronze color 

 and submetallic lustre. It is mostly in remnants of imperfect crystals 

 imbedded in the altered mineral in scales of a silver white color and pearly 

 lustre. I have also some specimens which are imperfect crystals having 

 a core of unaltered corundum, surrounded with subfibrous and fine scaly 

 margarite. 



I will mention that the locality formerly known as Village Green is now 

 Samuel Smith's farm (formerly Isaac Morgan's), Aston township, Delaware 

 c'ount}'. Pa. 



