Tinaksite
| Tinaksite | |
|---|---|
| General | |
| Category | Silicate mineral |
|
Formula (repeating unit) |
K2Na(Ca,Mn2+)2Ti[O|Si7O18(OH)] |
| Strunz classification | 9.DG.75 |
| Crystal system | Triclinic |
| Crystal class | Pinacoidal (1) (same H-M symbol) |
| Space group | P1 |
| Identification | |
| Color | Pink, Pale yellow, Light brown |
| Crystal habit | Fibrous, crystalline or Prismatic, crystalline, or Radial, crystalline |
| Cleavage | Perfect in one direction, indistinct in one direction |
| Mohs scale hardness | 6 |
| Luster | Vitreous to glassy |
| Streak | White |
| Diaphaneity | Transparent to Translucent |
| Specific gravity | 2.82 |
| Density | 2.82 |
| Optical properties | Biaxial (+) |
| Refractive index | nα = 1.593 nβ = 1.621 nγ = 1.666 |
| Birefringence | δ = 0.073 |
| References | |
Tinaksite (K2Na(Ca,Mn2+)2Ti[O|Si7O18(OH)]) is a mineral found in northern Russia. Tinaksite can be grayish-white, yellowish, orange, or brown, and it is often found in charoite. Its name is derived from its composition: titanium (Ti), sodium (Na) potassium (K) and silicon (Si). International Mineralogical Association first recognized tinaksite as a mineral in 1965.
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