ORDER IX.—PYRITINEA.
ARSENICAL SILVER. Argyrites Argenteus.
Arsenical Antimonial Silver, P. Arseniet of Silver , Thom. Arsenik-Silber, Jf. Argent Arsenical,J A e t'». Argent Antimonial Perro-Arsenifere, H.
476. Primary form : unknown ; occurs generally mannnilla-ted. or in curved lamellar distinct concretions, consisting of verythin crystalline coats.
H.=4. G.=9-4. Lustre shining or glimmering, metallic. Streakshining. Color nearly that of native silver, but usually tarnishedof a blackish color. Opaque. Fracture uneven. Sectile.
According to Klaproth , (Beitrage, i. 187,) the variety from Andreasberg contains,Silver 1275, Arsenic 35, Antimony 4, and Iron 44-25.
Before the blowpipe it affords a strong alliaceous odor, accompanying the fumesof the volatilized arsenic and antimony; and their remains a globule of impure sil-ver surrounded by a slag.
Obs. It occurs at Andreasberg , in the Hartz ; at Guadalcanal , in Estremadura , inSpain ; and at Kongsberg , in Norway , associated with antimonial silver, galena, andnative arsenic. The arsenical fumes under the blowpipe, and its liability to tarnish,distinguish it from the antimonial silver, for which it might be mistaken.
NICKEL STIBINE. Argyrites ectomus.
Eutomous Cobalt Pyrites, A/. Nickeliferous Gray Antimony, Nickelspiesglaserz, of the Germans .Aniimoine Sulfure Nickelifere, H.
477. Primary form : the cube. Cleavage parallel with P per-fect. Occurs also massive—structure granular.
H.=5—5-5. G.=6-451, a cleavable variety. Lustre metallic.Color steel-gray, inclining to silver-white. Brittle.
Nickel
36-60
25-25
Antimony
43-80
4775
Sulphur
17-71
15-25
Arsenic
—
11-75
Iron and Manganese
1-89=100, S.
In the blowpipe flame it is partly volatilized, and the charcoal is covered with awhite coating. Ultimately it fuses into a metallic globule, which communicates ablue color to glass of borax.
Obs. It occurs in the duchy of Nassau , in the mines near Freussberg, associatedwith sparry iron, galena, and copper pyrites.