Syngenite
K2Ca(SO4)2·H2OIMA symbol: Sgngrandfathered
Syngenite is a sulfate mineral with the formula K2Ca(SO4)2·H2O, crystallizing in the monoclinic system. It has a Mohs hardness of 2-5, typically colorless or white in color, with a vitreous luster, a specific gravity of 2.603. Its streak is white.
Photos
Crystallography
| Crystal system | monoclinic crystal systemWikidata (CC0) |
|---|---|
| Space group | P 1 21/m 1 |
| Cell (Å, °) | a = 9.77, b = 7.15, c = 6.25; α = 90, β = 104, γ = 90 |
| Cell volume | 423.628 ų, Z = 2 |
| Axial ratios | 1.3664:1:0.8741calculated from COD 9008128 |
| Source structure | COD 9008128 (Zeitschrift fur Kristallographie, 1967) |
Powder X-ray diffraction (calculated)
| d (Å) | 3.16 | 2.741 | 2.829 | 2.854 | 9.48 | 2.856 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 76.4 | 71 | 68.5 | 66.8 | 65.9 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9008128; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 2.575 g/cm³calculated from COD 9008128 |
|---|---|
| Hardness (Mohs) | 2-5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 2.603 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | colorless, 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 | 328.42 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | K 23.81%, Ca 12.2%, S 19.53%, O 43.85%, H 0.61% |
Classification
| Nickel-Strunz (10th) | 7.CD.35Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 7.CD.35Wikidata (CC0) |
| Dana (8th) | 29.3.1.1Wikidata (CC0) |