Leucite
K(AlSi2O6)IMA symbol: Lctapproved
Leucite is a silicate mineral with the formula K(AlSi2O6), crystallizing in the tetragonal system. It has a Mohs hardness of 5.5-6, typically white or gray in color, with a vitreous luster, a specific gravity of 2.45-2.5. Its streak is red.
Photos
Crystallography
| Crystal system | tetragonal crystal systemWikidata (CC0) |
|---|---|
| Space group | I 41/a :2 |
| Cell (Å, °) | a = 13.05476, b = 13.05476, c = 13.75182; α = 90, β = 90, γ = 90 |
| Cell volume | 2343.68 ų, Z = 16 |
| Axial ratios | 1.0000:1:1.0534calculated from COD 9001795 |
| Source structure | COD 9001795 (American Mineralogist, 1997) — 1 of 18 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.264 | 3.438 | 5.374 | 2.841 | 2.919 | 2.367 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 71.6 | 38 | 37.5 | 29.4 | 26.3 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9001795; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 2.474 g/cm³calculated from COD 9001795 |
|---|---|
| Hardness (Mohs) | 5.5-6single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 2.45-2.5 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | gray, whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) redsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 218.25 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | K 17.91%, Al 12.36%, Si 25.74%, O 43.99% |
Classification
| Nickel-Strunz (10th) | 9.GB.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.GB.05Wikidata (CC0) |
| Dana (8th) | 76.2.2.1Wikidata (CC0) |