Stibnite
| Stibnite | |
|---|---|
| General | |
| Category | Sulfide mineral |
| Formula | Sb2S3 |
| IMA symbol | Sbn |
| Strunz classification | 2.DB.05a |
| Crystal system | Orthorhombic |
| Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Space group | Pbnm |
| Unit cell | a = 11.229 Å, b = 11.31 Å, c = 3.8389 Å; Z = 4 |
| Identification | |
| Color | Lead-gray, tarnishing blackish or iridescent; in polished section, white |
| Crystal habit | Massive, radiating and elongated crystals. Massive and granular |
| Twinning | Rare |
| Cleavage | Perfect and easy on {010}; imperfect on {100} and {110} |
| Fracture | Subconchoidal |
| Tenacity | Highly flexible but not elastic; slightly sectile |
| Mohs scale hardness | 2 |
| Luster | Metallic |
| Streak | Lead grey |
| Diaphaneity | Opaque |
| Specific gravity | 4.63 |
| Optical properties | Anisotropic |
| Solubility | Decomposed with hydrochloric acid |
| References | |
| Major varieties | |
| Metastibnite | Earthy, reddish deposits |
Stibnite, sometimes called antimonite, is a sulfide mineral, a mineral form of antimony trisulfide (Sb2S3). It is a soft, metallic grey crystalline solid with an orthorhombic space group. It is the most important source for the metalloid antimony. The name is derived from the Greek στίβι stibi through the Latin stibium as the former name for the mineral and the element antimony.