Vermiculite
Mg0.7(Mg,Fe,Al)6(Si,Al)8O20(OH)4·8H2OIMA symbol: Vrmgrandfathered
Vermiculite is a silicate mineral with the formula Mg0.7(Mg,Fe,Al)6(Si,Al)8O20(OH)4·8H2O, crystallizing in the monoclinic system. It has a Mohs hardness of 1.3, a calculated density of 1.172 g/cm3.
Photos
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Crystallography
| Crystal system | monoclinic crystal systemWikidata (CC0) |
|---|---|
| Space group | C 1 c 1 |
| Cell (Å, °) | a = 5.33, b = 9.18, c = 28.9; α = 90, β = 97, γ = 90 |
| Cell volume | 1403.52 ų, Z = 4 |
| Axial ratios | 0.5806:1:3.1481calculated from COD 9000060 |
| Source structure | COD 9000060 (American Mineralogist, 1954) — 1 of 9 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 14.342 | 7.171 | 2.868 | 3.586 | 2.536 | 2.379 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 2.5 | 2.1 | 1.8 | 1.6 | 1.6 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9000060; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 1.172 g/cm³calculated from COD 9000060 |
|---|---|
| Hardness (Mohs) | 1.3single sourceWikidata (CC0) |
Classification
| Nickel-Strunz (10th) | 9.EC.50Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.EC.50Wikidata (CC0) |
| Dana (8th) | 71.2.Wikidata (CC0) |