antimony - Sciencemadness.org

42 THE METALLURGY OF ANTIMONY.
Pyrargyrite.
Composition.—Ag3SbS3 or 3Ag2S.Sb2S3.
Properties. — Rhombohedral. H. = 2'5. G. = 5*77-5-86. Lustre
metallic-adamantine. Colour black to grayish black ; by transmitted
light deep-red. Streak purplish red.
Occurrence. — At Andreasberg in the Harz; Freiberg, Saxony ;
Bohemia; and Kremnitz, Hungary.
Rivotite.
Composition.—Sb2O5, Ag2O, CuO, CaO, CO2.
Properties.—Amorphous, compact. H. —3*5-4. G. = 3*55-3 "62.
Colour yellowish green to grayish green. Streak grayish green.
Occurrence.—Sierra del Cadi.
Romeite.
Composition.—Antimonite of calcium, perhaps CaSb2O4.
Properties.—Tetragonal. H. = above 5*5. G. = 4*713. Colour
honey-yellow.
Occurrence.—Piedmont.
Sarawakite.
Composition.—May be antimony chloride.
Properties.—Minute crystals, probably tetragonal. Soft. Lustre
adamantine. Colourless or greenish yellow. Transparent.
Occurrence.—Found in native antimony in Borneo.
Schneebergite.
Composition.—Calcium and antimony with a little iron and traces
of copper, bismuth, zinc, magnesia, and sulphuric acid.
Properties.—Isometric. H. = 6*5. G. = 4*1. Lustre vitreous to
adamantine. Colour honey-yellow
Occurrence.—At Schneeberg.
Senarmontite.
Composition.—Sb2O3. 0=16-7; Sb = 83-3.
Properties.—Isometric, in octahedrons. Also granular; in crusts.
H. = 2-2'5. G. = 5'22-5*30. Lustre resinous, inclining to subadamantine.
Transparent to translucent. Colourless or grayish,
Streak white,