Natrosilite
Natrosilite is a rare silicate mineral that is colorless or white, transparent to translucent, with pearly luster and is soluble in water. Gems are very rare and mainly for collector’s of the unusual or collectors of water soluble gems. Natrosilite is named for NATRium (sodium), and SILicon in the composition.
The only source for gem quality specimens is the Palitra pegmatite, Kedykverpakhk Mt, Lovozero Massif, Kola Peninsula, Murmanskaja Oblast’, Northern Region, Russia. There is also an occurance of Natrosilite at the Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada but the specimens are far too small for gems.
Natrosilite distribution: on Mt. Karnasurt, Lovozero massif, and in the Khibiny massif, Kola Peninsula, Russia. At Mont Saint-Hilaire, Quebec, Canada.
| Chemical Formula: | Na2Si2O5 |
| Sodium Silicate | |
| Molecular Weight: | 182.15 gm |
| Composition: | Sodium | 25.24 % | Na | 34.03 % | Na2O |
| Silicon | 30.84 % | Si | 65.97 % | SiO2 | |
| Oxygen | 43.92 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Monoclinic – Prismatic |
| Crystal Habit: | Thick tabular pseudohexagonal crystals, to 6 cm; granular. |
| Twinning: | None |
| Cleavage: | Perfect on {100} (micaceous); distinct on {001}; poor on {011} |
| Fracture: | n/a |
| Tenacity: | Brittle |
| Moh’s Hardness: | n. d. |
| Density: | 2.48 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Other: | Soluble in water. |
| Color: | Colorless; anomalous blue interference colors in thin section |
| Transparency: | Transparent to translucent |
| Luster: | Pearly |
| Refractive Index: | 1.507 – 1.521 Biaxial ( + ) |
| Birefringence: | 0.014 |
| Dispersion: | None; r < v |
| Pleochroism: | None |
