250 Reéxamination of American Minerals. 
It is associated with the various ores of copper and Jead of the 
Wheatley mine, and sometimes so thoroughly diffused through the 
sulphate and carbonate of lead as to give them a uniform green 
tint. It is not found in any quantity. 
58. Azurite. 
This mineral, although rare, is nie in beautiful crystals some 
measuring from 4 to $ inch a of a deep blue color, and 
highly polished faces. Its sp. grav. is 3°88. € analysis gave, 
Carbonic acid, wie - re 24°98 
Oxyd of copper, - - - - - 69-41 
- - - - . : - 5°84 
100-23 
giving the formula 26u 6+6u H. 
This species occurs in similar associations with the malachite. 
It is however rarer. 
59. Zine Blende. 
Blende is found in considerable quantity both massive and crys- 
saaeas Some of the crystals are exceedingly beautiful, and of 
e, being three or four inches in diameter and with very 
brilliant surfaces. The colors are dark hair-brown and black, the 
brown being transparent. The specimens from this locality are 
hardly surpassed by those from any other mine. A specimen 
that was analyzed abba the as results : 
Sulphur, - : 33°82 
Zine, = , : . . : - 6439 
Cadmium, - - . = c ‘98 
Copper, - - ‘ : ns = = 32 
Lead, - 7 BS * ie ‘ “78 
10029 
It is proposed to examine yet other specimens, to see if there 
may not be larger amouats of cadmium contained in some of 
m. 
This mineral occurs in fluor spar, cale spar and quartz, more or 
less mixed with the other sulphurets. In some instances it is very 
peculiarly interlaced in the rocks; thus we have specimens con- 
sisting as it were of four layers, ‘na mely, granite, then compact 
crystallized quartz #ths of an inch thick, then the blende an inch 
thick, on that a layer of crystals of calc spar, and on this last 
fluor spar. 
60. Calamine. 
Calamine is found in delicate crystals of a silky lustre, forming 
in some instances snow-white tufts on fluor spar, blende and car- 
bonate of lime. It isalso found on cellular quartz. Some of the 
Specimens are quite handsome, having a blue and yellow color 
from the presence of carbonate of copper and oxyd of iron. No 
analysis was made of any of the specimens. 
