Ai’i’JiSDix. 
63 
33. Teteaiiedrite. 
Two varieties ot Tetrahedrite are found in North Carolina, the highly 
argentiferous (Freibergite,) containing ten and a half per cent, of silver ; 
it is associated with silver, zincblende, galenite, talc, magnesite, etc., at 
the McMakin Mine, Cabarrus county ; the other, which contains little or 
no silver, at George Ludwick’s Mine, in the same county. It is asso- 
ciated with chalcopyrite, scorodite, arscnosiderite etc. in a quartz vein. 
There is probably an occasional small admixture of argentiferous tet- 
rahedrite with the minerals associated with the native silver of Silver 
Hill, as they give before the blowpipe incrustations of antimony. 
III. COMPOUNDS OF CIILOPJNE, ETC. 
31. Halite or Common Salt. 
Found in the waters of the Atlantic Ocean, from which it can be 
obtained by evaporation, and in wells and springs at several points in 
the Triassic beds, e. g. in Chatham, Orange and Rockingham. 
35. Cerargyeite. 
In some of the gold ores of Scott’s Hill, in Burke county, silver is found 
after roasting ; a specimen, which I had an opportunity to examine, 
makes it probable that the silver is present as chloride of silver or cerar- 
gyrite. 
IV. FLUORINE COMPOUNDS. 
36. Fluorite. 
According to General Clingman, fluorite occurs at Prown Mountain. 
Burke county, also in Watauga, and with barite below Marshal, Madison 
county. 
37. Yttrocerite (?) 
A few minute deep violet blue spots were observed in association with 
pvrochlore, black tourmaline, orthoclase, quartz, etc. at Ray’s Mica 
Mine, Hurricane Mountain, Yancey county. 
