Anthophyllite
܆Mg2Mg5Si8O22(OH)2IMA symbol: Athredefined
Anthophyllite is a silicate mineral with the formula ܆Mg2Mg5Si8O22(OH)2, crystallizing in the orthorhombic system. It has a Mohs hardness of 5.5-6, typically brown, gray, green or yellow in color, with a pearly or vitreous luster, a specific gravity of 3.1-3.5. Its streak is gray or red.
Photos
Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | P n m a |
| Cell (Å, °) | a = 18.5, b = 17.89999, c = 5.27; α = 90, β = 90, γ = 90 |
| Cell volume | 1745.2 ų, Z = 4 |
| Axial ratios | 1.0335:1:0.2944calculated from COD 1010935 |
| Source structure | COD 1010935 (Zeitschrift fuer Kristallographie, Kristallgeometrie, Kristallphysik, Kristallchemie (-144,1977), 1930) — 1 of 3 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.039 | 3.633 | 2.534 | 2.82 | 3.326 | 2.669 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 66.4 | 56.7 | 45.3 | 38.8 | 38.4 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 1010935; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 2.968 g/cm³calculated from COD 1010935 |
|---|---|
| Hardness (Mohs) | 5.5-6single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 3.1-3.5 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Color | brown, gray, green, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | gray, redsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | pearly, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Classification
| Nickel-Strunz (10th) | 9.DE.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.DE.05Wikidata (CC0) |
| Dana (8th) | 66.1.2.1Wikidata (CC0) |