Specific Gravity: 4.6
Characteristics: Gray to black; perfect cleavage in one direction; opaque; metallic luster; bladed crystals; iridescent film on surface; powder produces orange solution when dissolved in concentrated HCl. Found in hydrothermal deposits.
Stibnite is used as a source for the native element antimony (Sb) which is used as a hardening alloy for lead, for use in storage batteries, etc. Antimony salts are also used in rubber and textile industries, medicine and in glassmaking.
(Primary text: Perkins, D. 2002. Mineralogy. Prentice Hall.)