Cassiterite
SnO2IMA symbol: Cstgrandfathered
Cassiterite is an oxide or hydroxide mineral with the formula SnO2, crystallizing in the tetragonal system. It has a Mohs hardness of 6-7, typically white, black, brown or gray in color, with an adamantine luster, a specific gravity of 6.5-7.1. Its streak is white or brown.
Photos
Crystallography
| Crystal system | tetragonal crystal systemWikidata (CC0) |
|---|---|
| Space group | P 42/m n m |
| Cell (Å, °) | a = 4.7357, b = 4.7357, c = 3.18732; α = 90, β = 90, γ = 90 |
| Cell volume | 71.482 ų, Z = 2 |
| Axial ratios | 1.0000:1:0.6730calculated from COD 2104743 |
| Source structure | COD 2104743 (Acta Crystallographica Section B, 2010) — 1 of 7 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.349 | 2.644 | 1.764 | 2.368 | 1.415 | 1.439 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 82.9 | 70.1 | 23.6 | 21.3 | 17.1 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 2104743; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 7.002 g/cm³calculated from COD 2104743 |
|---|---|
| Hardness (Mohs) | 6.5single sourceWikidata (CC0) 6-7single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 6.5-7.1 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | black, brown, gray, red, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | brown, gray, whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | adamantinesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 150.71 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Sn 78.77%, O 21.23% |
Classification
| Nickel-Strunz (10th) | 4.DB.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 4.DB.05Wikidata (CC0) |
| Dana (8th) | 4.4.1.5Wikidata (CC0) |