Charoite
.Charoite is found only in the Murun Massif, Chara River part of the Torgo River Basin, Aldan Shield, Southwest Yakutia (Sakha Republic), Eastern-Siberian Region, Russia. It had been found in 1947, but was not introduced to the world that is outside about 1978. This mineral that is breathtaking swirling colors of violet, purple and lavender and occassionally swirls of white Feldspar, yellow Canasite, orange Tinaksite and black Aegirine mixed in. Some specimens are beautifully chatoyant. The mineral is a product that is massive for making large items such as bookends and vases as well as cabochons. Cabochons look alive with swirling colors and chatoyance. The look of Charoite is unlike just about any mineral.
Charoite is named for the Chara River, Russia, near which it had been discovered. However, I have heard that the name arises from your message that is russianchary” this means “charms” or “magic” due to its beautiful chatoyance.
| Chemical Formula: | K(Ca,Na)2Si4O10(OH,F) • H2O |
| Hydrated Potassium Calcium Sodium Silicate Hydroxide Fluoride | |
| Molecular Weight: | 1,828.68 gm |
| Composition: | Potassium | 10.69 % | K | 12.88 % | K2O |
| Calcium | 17.53 % | Ca | 24.53 % | CaO | |
| Silicon | 27.65 % | Si | 59.14 % | SiO2 | |
| Hydrogen | 0.39 % | H | 3.45 % | H2O | |
| Oxygen | 43.75 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Monoclinic – Prismatic |
| Crystal Habit: | Fibrous, massive |
| Twinning: | None |
| Cleavage: | Good in three directions |
| Fracture: | Conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 5.0 – 6.0; VHN50=412 (kg/mm2) |
| Density: | 2.54 – 2.58 (g/cm3) |
| Luminescence: | Weakly Fluorescent; pale blue under SW UV and LV UV; yellow-orange cathodoluminescence |
| Radioactivity: | Barely Detectable, GRapi = 10.69 (Gamma Ray American Petroleum Institute Units) |
| Color: | Shades of lilac, violet and purple; colorless in thin section |
| Transparency: | Semitransparent to Opaque |
| Luster: | Vitreous to Pearly |
| Refractive Index: | 1.550 – 1.559 Biaxial ( + ) |
| Birefringence: | 0.0090 |
| Dispersion: | n/a |
| Pleochroism: | X = rose; Z = colorless, in thick fragments |
