Charoite
Charoite is a purple-hued gemstone discovered in the Chara River basin in Siberia, Russia. It was identified by Russian mineralogist V. Rogova, and was approved as a new mineral following the publication of her research in 1978. Its name is derived from the Russian word charo, meaning "to enchant."
Charoite is prized for the unique purple appearance created by its fibrous structure.
Basic Information
| English Name | Charoite |
|---|---|
| Japanese Name | Charo-seki |
| Chemical Composition | (K,Na)5(Ca,Ba,Sr)8[(OH,F)|Si6O16|Si10O25]・nH2O |
| Crystal System | Monoclinic (fibrous) |
| Hardness | 4.5–6 |
| Specific Gravity | 2.6 |
| Transparency | Translucent to opaque |
Characteristics & Varieties
- Formation: A contact metamorphic mineral formed in Archean crystalline schist or Paleozoic limestone/dolomite, influenced by the intrusion of Mesozoic alkali syenite.
- Color and Texture: Prized for the unique patterns created by its fibrous structure, displaying purple to lavender hues.
Varieties
- Charoite Cat's Eye: In stones where the crystal fibers are thin and aligned in parallel, a chatoyancy effect (a running band of light) can sometimes be observed.
Origin, Trade Names, Treatments & Similar Stones
Trade Names:
- Purple Jade: Sometimes used to describe dense sections lacking a fibrous structure.
- Russian Lavender Jade: A term similar to the one above.
Treatment: Dyeing (stones with lighter colors may be dyed with purple pigment).
Similar Stones:
- Stichtite: A mineral formed by the metamorphism of serpentine. Contains Cr. Discovered in Tasmania, Australia, and recognized as a new mineral in 1910. It can be distinguished by the presence of green coloration and a lower hardness of 1.5–2.5.
Caution: Hardness varies from 4.5 to 6. For processed items such as beads, it is recommended to handle them gently, keeping in mind potential surface scratches and the possibility of dyeing treatments.