Crystals, though rare, are pseudocubic or tabular and often twinned. Usual habits are massive, lamellar, granular, or acicular. It is pale silvery gray, with a gray streak. It is opaque, and the luster is brilliant metallic.
FORMATION Forms in hydrothermal veins with arsenic and silver, as well as galena, sphalerite, pyrite, and stibnite.
TESTS Burns white fumes in the air; turns flame greenish blue.
Group: NATIVE ELEMENTS
Composition: Sb
Hardness: 3–3½
SG: 6.69
Cleavage: Perfect basal
Fracture: Uneven
