Epsomite
Mg(SO4)·7H2OIMA symbol: Esmgrandfathered
Epsomite is a sulfate mineral with the formula Mg(SO4)·7H2O, crystallizing in the orthorhombic system. It has a Mohs hardness of 2-2.5, typically white in color, with an earthy or vitreous luster, a specific gravity of 1.751. Its streak is white.
Photos
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Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | P 21 21 21 |
| Cell (Å, °) | a = 11.8664, b = 12.015, c = 6.8598; α = 90, β = 90, γ = 90 |
| Cell volume | 978.035 ų, Z = 4 |
| Axial ratios | 0.9876:1:0.5709calculated from COD 9017892 |
| Source structure | COD 9017892 (Atti della Societa Toscana di Scienze Naturali, Memorie, Serie A, 2019) — 1 of 5 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 4.223 | 4.204 | 2.68 | 5.36 | 2.662 | 2.88 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 91.3 | 33.2 | 32.7 | 30.9 | 28.9 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9017892; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 1.71 g/cm³calculated from COD 9017892 |
|---|---|
| Hardness (Mohs) | 2single sourceWikidata (CC0) 2-2.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 1.751 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | earthy, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 246.47 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Mg 9.86%, S 13.01%, O 71.4%, H 5.73% |
Classification
| Nickel-Strunz (10th) | 7.CB.40Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 7.CB.40Wikidata (CC0) |
| Dana (8th) | 29.6.11.1Wikidata (CC0) |