Bassanite
Ca(SO4)·0.5H2OIMA symbol: Bssgrandfathered
Bassanite is a sulfate mineral with the formula Ca(SO4)·0.5H2O, crystallizing in the monoclinic system. It has a Mohs hardness of 2.5-3, typically red in color, with an adamantine or vitreous luster, a specific gravity of 5.9-6.1. Its streak is orange or yellow.
Photos
Crystallography
| Crystal system | monoclinic crystal systemWikidata (CC0) |
|---|---|
| Space group | P 31 2 1 |
| Cell (Å, °) | a = 6.968, b = 6.968, c = 6.41; α = 90, β = 90, γ = 120 |
| Cell volume | 269.529 ų, Z = 3 |
| Axial ratios | 1.0000:1:0.9199calculated from COD 9017339 |
| Source structure | COD 9017339 (Acta Crystallographica, Section C, 1983) — 1 of 19 structures |
Physical properties
| Density (calculated) | 2.756 g/cm³calculated from COD 9017339 |
|---|---|
| Hardness (Mohs) | 2.5-3single sourceFord, Dana's Textbook of Mineralogy, 3rd ed. (1922) |
| Specific gravity | 5.9-6.1 g/cm3single sourceFord, Dana's Textbook of Mineralogy, 3rd ed. (1922) |
| Color | redsingle sourceFord, Dana's Textbook of Mineralogy, 3rd ed. (1922) |
| Streak | whitesingle sourceWikidata (CC0) orange, yellowsingle sourceFord, Dana's Textbook of Mineralogy, 3rd ed. (1922) |
| Luster | adamantine, vitreoussingle sourceFord, Dana's Textbook of Mineralogy, 3rd ed. (1922) |
Chemistry (calculated)
| Molecular weight | 145.15 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Ca 27.61%, S 22.09%, O 49.6%, H 0.69% |
Classification
| Nickel-Strunz (10th) | 7.CD.45Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 7.CD.45Wikidata (CC0) |