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| Mineral Name: |
charoite |
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| Gem Names: |
charoite |
| Chemistry: |
K(Na, Ca)11(Ba, Sr)Si18O46(OH, F) - n H2O or -
(Ca,K,Na)3Si4O10(OH,F) - H2O or
K5Ca8Si18O46(OH) - 3(H2O) |
| Class: |
silicate (inosilicate) |
| Crystal Sys: |
monoclinic |
| Hardness: |
5 |
Specific Gravity: |
2.5 - 2.8 |
| Fracture: |
conchoidal |
Refractive Index: |
translucent - opaque |
| Dispersion: |
none |
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| Misc Prop: |
Take your choice of chemistry, there are many formulas listed for charoite mostly similar but not identical. The colorant has not been identified.
Although it is a mineral, it is sold in the gem trade as a mixed mineral rock. It usually contains aergirine-augite, tinaksite, and microcline feldspar. It has a feathery structure with the main color coming from the charoite (a purple to magenta color). It can often beee seen with interlocking crystals and sometimes (rarely) has a bit of chatoyancy.
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| Color: |
In gemstones, color, is often the key to naming or describing the particular variety. Hence look for this information below in the various descriptions. Color, opacity, and homogeneity often determine the placement of value on any given stone, and are all optical properties of the particular stone. |
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