Amarantite
Fe3+2O(SO4)2·7H2OIMA symbol: Amagrandfathered
Amarantite is a sulfate mineral with the formula Fe3+2O(SO4)2·7H2O, crystallizing in the triclinic system. It has a Mohs hardness of 2-5, typically brown, orange or red in color, a specific gravity of 2.11. Its streak is yellow; cleavage is perfect.
Photos
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Crystallography
| Crystal system | triclinic crystal systemWikidata (CC0) |
|---|---|
| Space group | P -1 |
| Cell (Å, °) | a = 6.6548, b = 8.9204, c = 11.6053; α = 97.26, β = 95.634, γ = 90.383 |
| Cell volume | 679.979 ų, Z = 4 |
| Axial ratios | 0.7460:1:1.3010calculated from COD 9017474 |
| Source structure | COD 9017474 (ICSD Communications, 2018) — 1 of 6 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 8.847 | 11.455 | 3.103 | 3.173 | 3.646 | 3.647 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 65.3 | 15.5 | 13 | 12.4 | 12.1 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9017474; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 2.178 g/cm³calculated from COD 9017474 |
|---|---|
| Hardness (Mohs) | 2-5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 2.11 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | brown, orange, redsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | lemonsingle sourceWikidata (CC0) yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Cleavage | perfectDana, System of Mineralogy, 6th ed. (1892) |
Classification
| Nickel-Strunz (10th) | 7.DB.30Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 7.DB.30Wikidata (CC0) |