Boulangerite
Pb5Sb4S11IMA symbol: Bougrandfathered
Boulangerite is a sulfide or sulfosalt mineral with the formula Pb5Sb4S11, crystallizing in the monoclinic system. It has a Mohs hardness of 2.5-3, typically gray, red or yellow in color, with a metallic luster, a specific gravity of 5.75-6. Its streak is black.
Photos
Crystallography
| Crystal system | monoclinic crystal systemWikidata (CC0) |
|---|---|
| Space group | P 1 21/a 1 |
| Cell (Å, °) | a = 21.554, b = 23.454, c = 8.079; α = 90, β = 100.76, γ = 90 |
| Cell volume | 4012.35 ų, Z = 4 |
| Axial ratios | 0.9190:1:0.3445calculated from COD 9014250 |
| Source structure | COD 9014250 (The Canadian Mineralogist, 2012) — 1 of 5 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.724 | 2.02 | 2.809 | 2.785 | 3.727 | 3.217 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 56.8 | 46.9 | 45.5 | 43 | 42.2 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9014250; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 6.233 g/cm³calculated from COD 9014250 |
|---|---|
| Hardness (Mohs) | 2.75single sourceWikidata (CC0) 2.5-3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 5.75-6 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Color | gray, red, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | blacksingle sourceWikidata (CC0) |
| Luster | metallicsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 1875.75 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Pb 55.23%, Sb 25.97%, S 18.8% |
Classification
| Nickel-Strunz (10th) | 2.HC.15Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 2.HC.15Wikidata (CC0) |
| Dana (8th) | 3.5.2.1Wikidata (CC0) |