Boulangerite
| Boulangerite | |
|---|---|
Boulangerite, covering a block of limestone | |
| General | |
| Category | Sulfosalt minerals |
| Formula | Pb5Sb4S11 |
| IMA symbol | Bou |
| Strunz classification | 2.HC.15 |
| Crystal system | Orthorhombic |
| Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Space group | Pnam |
| Unit cell | 4,027.99 |
| Identification | |
| Cleavage | Good Distinct on {100} Indistinct on {001} and {010} |
| Fracture | Brittle |
| Tenacity | Brittle |
| Mohs scale hardness | 2.5–3 |
| Luster | Metallic |
| Streak | Reddish brown to black |
| Density | 5.9–6.2 |
| Pleochroism | Weak |
| Ultraviolet fluorescence | None |
| Melting point | Around 525 °C |
| Fusibility | Around 525 °C |
| Solubility | Completely soluble in hydrochloric acid Partially soluble in nitric acid |
| Common impurities | Cu, Zn, Sn, Fe |
Boulangerite or antimonbleiblende is an uncommon monoclinic orthorhombic sulfosalt mineral, lead antimony sulfide, formula Pb5Sb4S11. It was named in 1837 in honor of French mining engineer Charles Boulanger (1810–1849), and had been a valid species since pre-IMA. It was first described prior to 1959, and is now grandfathered.