Wollastonite
CaSiO3IMA symbol: Woapproved
Wollastonite is a silicate mineral with the formula CaSiO3, crystallizing in the triclinic system. It has a Mohs hardness of 4.5-5, typically white, brown, gray or red in color, with a pearly or vitreous luster, a specific gravity of 2.8-2.9. Its streak is white.
Photos
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Crystallography
| Crystal system | triclinic crystal systemWikidata (CC0) |
|---|---|
| Space group | P -1 |
| Cell (Å, °) | a = 7.9258, b = 7.3202, c = 7.0653; α = 90.055, β = 95.217, γ = 103.426 |
| Cell volume | 396.96 ų, Z = 6 |
| Axial ratios | 1.0827:1:0.9652calculated from COD 9005777 |
| Source structure | COD 9005777 (Physics and Chemistry of Minerals, 1984) — 1 of 4 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.979 | 2.975 | 3.317 | 3.09 | 1.83 | 3.517 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 99.5 | 55.5 | 40.6 | 40 | 39.5 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9005777; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 2.916 g/cm³calculated from COD 9005777 |
|---|---|
| Hardness (Mohs) | 4.5-5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 2.8-2.9 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | brown, gray, red, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | pearly, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 116.16 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Ca 34.5%, Si 24.18%, O 41.32% |
Classification
| Nickel-Strunz (10th) | 9.DG.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.DG.05Wikidata (CC0) |
| Dana (8th) | 65.2.1.1cWikidata (CC0) |