Boulangerite | |
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General | |
Category | Sulfosalt minerals |
Formula (repeating unit) | Pb5Sb4S11 |
IMA symbol | Bou[1] |
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.[2] It was named in 1837 in honor of French mining engineer Charles Boulanger (1810–1849),[3] and had been a valid species since pre-IMA. It was first described prior to 1959, and is now grandfathered.[4]