Xonotlite
Xonotlite is an extemely rare gem since gem quality crystals are very rare. The chemical formula of Xonotlite is Ca6Si6O17(OH)2 (Calcium Silicate Hydroxide) and its molecular weight is 714.99 gm. It is usually found as very small, very thin needlelike crystals or as flaky fibrous radiating bundles and rosettes. Xonotlite has a specific gravity of 2.70 – 2.72 (g/cm3) and the refractive index of 1.583 – 1.595 Biaxial ( + ). Crystals are translucent at best.
There are quite a few localities for finding non-gem quality material that is very attractive and collectable as mineral specimens but gemmy crystals are extremely rare.
| Category: | Inosilicates | |||||||||||||||||||||||||
| Chemical Formula: | Ca6Si6O17(OH)2 | |||||||||||||||||||||||||
| Calcium Silicate Hydroxide | ||||||||||||||||||||||||||
| Molecular Weight: | 714.99 gm | |||||||||||||||||||||||||
| Composition: |
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| Crystallography: | Monoclinic – Prismatic |
| Crystal Habit: | As needlelike crystals, elongated, to 2 cm, with striated prism zones and tapering terminations; as flaky fibrous radiating bundles and rosettes; massive. |
| Twinning: | None |
| Cleavage: | [001] Perfect |
| Fracture: | Splintery |
| Tenacity: | Tough |
| Moh’s Hardness: | 6.0 – 6.5 |
| Density: | 2.70 – 2.72 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Colorless, White to Chalky White, Gray, light Gray, pale Pink, fading on exposure |
| Transparency: | Translucent |
| Luster: | Vitreous, Pearly, Silky |
| Refractive Index: | 1.583 – 1.595 Biaxial ( + ) |
| Birefringence: | 0.0120 |
| Dispersion: | Very Low |
| Pleochroism: | None |
