charoite
Sign in to saveCharoite ( ) is a rare silicate mineral with the chemical composition , first described in 1978. It is named after the Chara River, despite its being away from the discovery place. When it was discovered, it was thought to be a fake, dyed purple to give it its striking appearance.
Key facts
- Mineral.name
- Charoite
- Mineral.category
- Silicate mineral
- Mineral.boxbgcolor
- e181de
- Mineral.image
- Czaroit1.jpg
- Mineral.IMAsymbol
- Cha
- Mineral.system
- Monoclinic
- Mineral.class
- Prismatic (2/m) (same H-M symbol)
- Mineral.symmetry
- P21/m
- Mineral.color
- Violet, lilac, light brown
- Mineral.habit
- Fibrous, massive
- Mineral.cleavage
- Good in three directions
- Mineral.fracture
- Conchoidal
- Mineral.mohs
- 5 - 6
- Mineral.luster
- Vitreous to pearly
- Mineral.refractive
- nα = 1.550 nβ = 1.553 nγ = 1.559
- Mineral.opticalprop
- Biaxial (+)
- Mineral.birefringence
- 0.009
- Mineral.fluorescence
- Weakly fluorescent
via Wikipedia infobox
Article
4 sectionsContents
- Properties
- Occurrences
- Gallery
- References
Charoite ( ) is a rare silicate mineral with the chemical composition , first described in 1978. It is named after the Chara River, despite its being away from the discovery place. When it was discovered, it was thought to be a fake, dyed purple to give it its striking appearance.
== Properties == Charoite is translucent lavender to purple in color with a pearly luster. Charoite is strictly massive in nature, and fractures are conchoidal. It has an unusual swirling, fibrous appearance, sometimes chatoyant, and that, along with its intense color, can lead many to believe at first that it is synthetic or enhanced artificially. Though reportedly discovered in the 1940s, it was not known to most of the world until its description in 1978. It is said to be opaque and unattractive when found in the field; a fact that may have contributed to its late recognition. Charoite consists of oxygen (43.75%), silicon (27.65%) and calcium (17.53%) mainly, but its composition includes potassium (10.69%) - which gives it its radioactive properties - and hydrogen (0.39%) as well. It has a barely detectable, 0.65% radioactivity concentration per Gamma Ray American Petroleum Institute Units.