Langbeinite
K2Mg2(SO4)3IMA symbol: Lbngrandfathered
Langbeinite is a sulfate mineral with the formula K2Mg2(SO4)3, crystallizing in the cubic system. It has typically colorless in color, a specific gravity of 1.477.
Photos




Crystallography
| Crystal system | cubic crystal systemWikidata (CC0) |
|---|---|
| Space group | P 21 3 |
| Cell (Å, °) | a = 10.1073, b = 10.1073, c = 10.1073; α = 90, β = 90, γ = 90 |
| Cell volume | 1032.54 ų, Z = 4 |
| Axial ratios | 1.0000:1:1.0000calculated from COD 9005867 |
| Source structure | COD 9005867 (Physics and Chemistry of Minerals, 1988) — 1 of 7 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.196 | 2.701 | 1.64 | 1.982 | 3.047 | 2.063 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 48.1 | 17.2 | 16 | 13.3 | 11.5 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9005867; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.064 g/cm³calculated from COD 9005867 |
|---|---|
| Specific gravity | 1.477 g/cm3single sourceDana's System, 2nd Appendix (1909) |
| Color | colorlessFord, Dana's Textbook of Mineralogy, 3rd ed. (1922) |
Chemistry (calculated)
| Molecular weight | 414.99 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | K 18.84%, Mg 11.71%, S 23.18%, O 46.26% |
Classification
| Nickel-Strunz (10th) | 7.AC.10Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 7.AC.10Wikidata (CC0) |
| Dana (8th) | 28.4.4.1Wikidata (CC0) |