Beudantite
PbFe3+3(AsO4)(SO4)(OH)6IMA symbol: Bdnredefined
Beudantite is a phosphate, arsenate, or vanadate mineral with the formula PbFe3+3(AsO4)(SO4)(OH)6, crystallizing in the trigonal system. It has a Mohs hardness of 3-5, typically black, brown or green in color, with an adamantine or resinous luster, a specific gravity of 4.002-5. Its streak is gray or yellow.
Photos
Crystallography
| Crystal system | trigonal crystal systemWikidata (CC0) |
|---|---|
| Space group | R -3 m :H |
| Cell (Å, °) | a = 7.315, b = 7.315, c = 17.0355; α = 90, β = 90, γ = 120 |
| Cell volume | 789.431 ų, Z = 3 |
| Axial ratios | 1.0000:1:2.3288calculated from COD 9004195 |
| Source structure | COD 9004195 (The Canadian Mineralogist, 1988) |
Powder X-ray diffraction (calculated)
| d (Å) | 3.075 | 5.938 | 3.658 | 1.979 | 2.272 | 1.829 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 71.4 | 39.8 | 27.7 | 25.2 | 21 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9004195; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 4.391 g/cm³calculated from COD 9004195 |
|---|---|
| Hardness (Mohs) | 3-5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 4.002-5 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | black, brown, greenDana, System of Mineralogy, 6th ed. (1892) |
| Streak | gray, yellowDana, System of Mineralogy, 6th ed. (1892) |
| Luster | adamantine, resinous, vitreousDana, System of Mineralogy, 6th ed. (1892) |
Classification
| Nickel-Strunz (10th) | 8.BL.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 8.BL.05Wikidata (CC0) |
| Dana (8th) | 43.4.1.1Wikidata (CC0) |