Tinaksite
Appearance
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 | [1][2][3] |
Tinaksite (K2Na(Ca,Mn2+)2Ti[O|Si7O18(OH)])[2] is a mineral found in northern Russia. Tinaksite can be grayish-white, yellowish, orange, or brown,[1] and it is often found in charoite.[4] 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.
References
External links
- Rozhdestvenskaya, I. V.; Nikishova, L. V.; Lazebnik, Y. D.; Lazebnik, K. A. (1989). "Thecrystal structure of tokkoite andits relation to the structure of tinaksite" (PDF). Zeitschrift für Kristallographie: 195–204. doi:10.1524/zkri.1989.189.14.195.
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