Gedrite
܆Mg2(Mg3Al2)(Si6Al2)O22(OH)2IMA symbol: Gedredefined
Gedrite is a silicate mineral with the formula ܆Mg2(Mg3Al2)(Si6Al2)O22(OH)2, crystallizing in the orthorhombic system. It has a specific gravity of 3.976. Its streak is white.
Photos
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Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | P n m a |
| Cell (Å, °) | a = 18.531, b = 17.741, c = 5.249; α = 90, β = 90, γ = 90 |
| Cell volume | 1725.65 ų, Z = 4 |
| Axial ratios | 1.0445:1:0.2959calculated from COD 9000210 |
| Source structure | COD 9000210 (American Mineralogist, 1970) |
Powder X-ray diffraction (calculated)
| d (Å) | 3.043 | 8.213 | 2.525 | 8.87 | 3.204 | 2.802 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 78.1 | 69.5 | 64.4 | 55.6 | 54.9 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9000210; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.188 g/cm³calculated from COD 9000210 |
|---|---|
| Specific gravity | 3.976 g/cm3single sourceDana's System, 2nd Appendix (1909) |
| Streak | whitesingle sourceWikidata (CC0) |
Classification
| Nickel-Strunz (10th) | 9.DD.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.DE.05Wikidata (CC0) |
| Dana (8th) | 66.1.2.5Wikidata (CC0) |