Almandine
Fe2+3Al2(SiO4)3IMA symbol: Almgrandfathered
Almandine is a silicate mineral with the formula Fe2+3Al2(SiO4)3, crystallizing in the cubic system. It has a Mohs hardness of 7.5, a calculated density of 3.929 g/cm3. Its streak is white.
Photos
Crystallography
| Crystal system | cubic crystal systemWikidata (CC0) |
|---|---|
| Space group | I a -3 d |
| Cell (Å, °) | a = 11.565, b = 11.565, c = 11.565; α = 90, β = 90, γ = 90 |
| Cell volume | 1546.81 ų, Z = 8 |
| Axial ratios | 1.0000:1:1.0000calculated from COD 9006320 |
| Source structure | COD 9006320 (Physics and Chemistry of Minerals, 1995) — 1 of 17 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.586 | 1.545 | 2.891 | 1.604 | 1.876 | 2.361 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 44.1 | 37.2 | 33.3 | 21.7 | 20.1 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9006320; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.929 g/cm³calculated from COD 9006320 |
|---|---|
| Hardness (Mohs) | 7.5single sourceWikidata (CC0) |
| Streak | whitesingle sourceWikidata (CC0) |
Classification
| Nickel-Strunz (10th) | 9.AD.25Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.AD.25Wikidata (CC0) |
| Dana (8th) | 51.4.3a.2Wikidata (CC0) |