Tschermigite
(NH4)Al(SO4)2·12H2OIMA symbol: Tmigrandfathered
Tschermigite is a sulfate mineral with the formula (NH4)Al(SO4)2·12H2O, crystallizing in the cubic system. It has a Mohs hardness of 1-2, typically white in color, with a vitreous luster, a specific gravity of 1.5. Its streak is white.
Photos
_-_Tschermig,_B%C3%B6hmen.jpg){kind=link}
Crystallography
| Crystal system | cubic crystal systemWikidata (CC0) |
|---|---|
| Space group | P a -3 |
| Cell (Å, °) | a = 12.248, b = 12.248, c = 12.248; α = 90, β = 90, γ = 90 |
| Cell volume | 1837.36 ų, Z = 4 |
| Axial ratios | 1.0000:1:1.0000calculated from COD 9008299 |
| Source structure | COD 9008299 (Zeitschrift fur Kristallographie, 1981) — 1 of 4 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.273 | 4.33 | 4.083 | 5.477 | 7.071 | 2.81 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 92.1 | 68.5 | 52.4 | 42.2 | 34.9 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9008299; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 1.639 g/cm³calculated from COD 9008299 |
|---|---|
| Hardness (Mohs) | 1-2single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 1.5 g/cm3Dana, System of Mineralogy, 6th ed. (1892) |
| Color | whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) |
| Luster | vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 453.33 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | N 3.09%, H 6.23%, Al 5.95%, S 14.15%, O 70.59% |
Classification
| Nickel-Strunz (10th) | 7.CC.20Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 7.CC.20Wikidata (CC0) |