Kermesite
Sb2OS2IMA symbol: Kemgrandfathered
Kermesite is a sulfide or sulfosalt mineral with the formula Sb2OS2, crystallizing in the triclinic system. It has a Mohs hardness of 1-1.5, typically red in color, with an adamantine or metallic luster, a specific gravity of 4.5-4.6. Its streak is brown or red.
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Crystallography
| Crystal system | triclinic crystal systemWikidata (CC0) |
|---|---|
| Space group | P -1 |
| Cell (Å, °) | a = 8.147, b = 10.709, c = 5.785; α = 102.78, β = 110.63, γ = 101 |
| Cell volume | 440.229 ų, Z = 4 |
| Axial ratios | 0.7608:1:0.5402calculated from COD 9009342 |
| Source structure | COD 9009342 (Neues Jahrbuch fur Mineralogie, Monatshefte, 1987) — 1 of 2 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.702 | 4.078 | 2.921 | 2.922 | 3.14 | 5.297 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 95.3 | 90.1 | 85.8 | 75.5 | 71.7 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9009342; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 4.883 g/cm³calculated from COD 9009342 |
|---|---|
| Hardness (Mohs) | 1-1.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 4.5-4.6 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Color | redsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | brown, redsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | adamantine, metallicsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 323.65 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Sb 75.24%, O 4.94%, S 19.81% |
Classification
| Nickel-Strunz (10th) | 2.FD.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 2.FD.05Wikidata (CC0) |
| Dana (8th) | 2.13.1.1Wikidata (CC0) |