Levyne-Na
Na6(Si12Al6)O36 • 18H2O [CNMNC approved formula]
Named as the sodium-dominant member of levyne serires. Species named for Armand Lévy (1794-1841), French mineralogist and crystallographer, Paris University, France. Named per nomenclature for zeolite minerals (IMA, 1997).
| IMA status : | Approved Species 1997 () |
| CLASSIFICATION | |
| Dana (8th edition) : |
77.01.02.08a (This Dana# Added) |
| (77) Tectosilicate Zeolite group | |
| (77.01) true zeolites | |
| (77.01.02) Chabazite and related species | |
| Nickel-Strunz (10th edition) : |
09.GD.15 |
| (09) Silicates | |
| (09.G) Tektosilicates with Zeolitic H2O | |
| (09.GD) Chains of 6-membered rings - tabular zeolites | |
| Crystal system: | Trigonal System |
| Point group (H-M): | 3m (or 3 2/m) — hexagonal-scalenohedral |
| Space group: | R3m |
| Unit cell: | a = 13.338(4)Å, c = 23.014(9)Å, V=3 |
| Crystal Habit: | Crystals are thin tabular ⊥ {0001}, with faces typically striated and {0001} rounded, to 3 cm; in sheaf-like or confused aggregates. |
| Twinning: | Penetration twins on {0001} ubiquitous |
| Color: | Colorless, white; stained grayish, greenish, reddish, yellowish by impurities; colorless in thin section |
| Diaphaneity: | Transparent to translucent |
| Luster: | Vitreous |
| Hardness (Mohs): | 4 - 4.5 |
| Cleavage: | {1011}, indistinct |
| Tenacity: | Brittle |
| Fracture: | Subconchoidal to uneven |
| Geologic Setting: | Typically as a crystalline lining in cavities in basalts. |
| Mineral Association: | Zeolites, especially offretite and erionite |
Clusters of white platy levyne-(Na) crystals in cavities in volcanic matrixOrigin: Browns Bay, Island Mage, Co. Antrim, N. Ireland
Sample size: micromount
Photo: Diederik Visser
(zoom-in of above)