Andradite
Ca3Fe3+2(SiO4)3IMA symbol: Adrgrandfathered
Andradite is a silicate mineral with the formula Ca3Fe3+2(SiO4)3, crystallizing in the cubic system. It has typically black, brown or red in color, a specific gravity of 4.25. Its streak is white.
Photos
Crystallography
| Crystal system | cubic crystal systemWikidata (CC0) |
|---|---|
| Space group | I a -3 d |
| Cell (Å, °) | a = 12.0643, b = 12.0643, c = 12.0643; α = 90, β = 90, γ = 90 |
| Cell volume | 1756 ų, Z = 8 |
| Axial ratios | 1.0000:1:1.0000calculated from COD 2101484 |
| Source structure | COD 2101484 (Acta Crystallographica Section B, 1996) — 1 of 38 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.698 | 1.612 | 2.463 | 3.016 | 1.673 | 4.265 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 92.8 | 76.9 | 75.3 | 29.5 | 24.5 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 2101484; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.845 g/cm³calculated from COD 2101484 |
|---|---|
| Specific gravity | 4.25 g/cm3single sourceFord, Dana's Textbook of Mineralogy, 3rd ed. (1922) |
| Color | black, brown, redsingle sourceFord, Dana's Textbook of Mineralogy, 3rd ed. (1922) |
| Streak | whitesingle sourceWikidata (CC0) |
Classification
| Nickel-Strunz (10th) | 9.AD.25Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.AD.25Wikidata (CC0) |
| Dana (8th) | 51.4.3b.1Wikidata (CC0) |