Mineralogy and Geology. 277 
Sulphuret of Nickel in Pennsylvania —This Journal, xiiiy 117. 
Erubescite and Copper Pyrites of the Espedal Copper Works, Nor- 
way; Mr. Davip Forzes, (Jameson’s Edinb. Jour., |, 278.)—The eru- 
bescite has the sp. gr. 4-432, at 60° F. Composition :— 
8 Cu Fe n Si 
24:49 59°71 11:12 0'1 8°83 = 99°15 
This corresponds to the formula 7€uS+Fe? S4= sulphur 25°23, copper 
63:17, iron 11-60=100. Mr. Forbes reviews various analyses of this 
mineral, and concludes that the species is a compound of a protosul- 
phuret and disulphuret of copper, with more or less of the copper re- 
placed by iron. He thus deduces the formule : 
20u? S+Cu §, (corresponding to § 23-28, Ou (with Fe) 76°62==100)—for the Kil- 
larney mineral, analyzed by Phillips. 
Cu? S+CuS (corresponding to S 2531, Cu (with Fe) 74:69), for the above ore, 
and that analyzed by emann, Plattner and Hisinger 
Py 
isinger. 
Cu? S+2Cu §, (corresponding to § 27°60, Cu 72°40), for the crystallized ore analyzed 
» by Plattner, 
Digenite is included under the last, it being a variety containing no iron. 
he copper pyrites has the hardness 3°5, and G. (at 60° F,)=4°185. 
. 
Composition obtained — 
S Cu Fe Mn Si 
33°88 82:65 82°77 trace 0°32 = 99°62 
Analyses and descriptions of Fahlerz, Copper glance, Chalcopyrite, 
Erubescite, Zigueline, of ae : Re jb Bscu1.—This Jour- 
nal, xiv, 60. 
Chalcotrichite at the Perkiomen Lead mine.—This Journal, xiii, 117. 
On the Galmei of Weisloch in Baden; by Gustav Herta, Dr. Phi- 
los. Inaug.-dissert., 46 pp. 8vo. Heidelberg, 1851. 
Analysis of Marmatite and oxyd of Zinc from Tuscany ; MENEGHINI 
and Becut.—This Journal, xiv, 60. 
” the Lead ores of Chester Co., Pennsylvania.—This Journal, 
xill, 116, 
Analyses and deseriptions of Galena and Feather ore of Tuscany ; 
Meneeuini and Becni.—This Journal, xiv, 60. 
Platinum and Iridosmine in California; Dr. F. A. Gent, (Proc. 
Acad. Nat. Sci. Philad., vi, 113).-—A few steel-colored rounded grains of 
platinum were observed amon specimens of gold from the American 
and assumed yellow orange @ 
Genth, on trying the Ural iridosmine, found that the lead-colored scales 
afforded the same colors; and he suggests that this may be a good test 
for distinguishing the Sisserskite from the Newjanskite. He adds that 
there are probably in nature only two distinct compounds of iridium and 
osmium, viz: IrOs* 
& mixture of the two. 
