Reéramination of American Minerals. (249 
with modified edges and angles, octahedron and rhombic dodeca- 
hedron often very much flattened out and occasionally rounded 
sulphur. 
The galena is argentiferous, giving an average yield of thirty 
ounces to the ton. It is found associated with quartz, calcite and 
fluor spar, frequently inserted in the crystals of these substances ; it 
is also.a common associate of all the minerals of this locality. 
f 
frequently contain sulphur. i ate oa 
55. Copper. Ps, 
Native copper is found only in delicate films on hematite, or 
quartz crystal, and forms an interposing layer between the hema- 
tite and copper pyrites. 
56. Copper Pyrites. 
Copper pyrites is found in some cases in sufficient quantity to be 
worked as an ore; some of the masses are of considerable size 
weighing three or four hundred pounds. Fine crystals are ob- 
tained, both tetrahedral and octahedral. It affords on analysis 
Sulphur, - 4 
Copper, - * - - . - 32°85 
Tron, - + - - - - 29°93 
Lead, - - - - - « 25 
It occurs alone and associated with the other sulphurets. It is 
found in various parts of the vein, there being no special point 
of deposit. 
57. Malachite. 
Malachite occurs in small reniform masses, consisting of fibrous 
crystals, and of a bright green color; also in silky tufts of a very 
light green color, which are associated with azurite and car- 
ear ge id, n1-46 
xyd of co - - : * 2 e 
Agha are 9-02 
Oxyd of iron, - - - i aa hak y ‘12 
affording the formula Gu 6+Cu H 
Srconp Senres, Vol. XX, No. 59.—Sept., 1855. 32 
