| Anandite | |
|---|---|
| General | |
| Category | Phyllosilicate minerals |
| Group | Mica group, brittle mica group |
| Formula | (Ba,K)(Fe2+,Mg)3(Si,Al,Fe)4O10(S,OH)2 |
| IMA symbol | Ana[1] |
| Strunz classification | 9.EC.35 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (sameH-M symbol) |
| Space group | C2/m |
| Unit cell | a = 5.412(5), b = 9.434(5) c = 19.953(10) [Å]; β = 95°; Z = 2 |
| Identification | |
| Color | Black |
| Crystal habit | Massive, prismatic crystals poorly formed produce hexagonal outline cleavage fragments |
| Cleavage | Perfect on {001} |
| Fracture | Flexible fragments |
| Mohs scale hardness | 3 – 4 |
| Luster | Vitreous |
| Streak | Grey white |
| Diaphaneity | Nearly opaque |
| Specific gravity | 3.94 |
| Optical properties | Biaxial (+) |
| Refractive index | nα = 1.855 nγ = 1.880 |
| Pleochroism | Y = green; Z = brown |
| References | [2][3][4] |
Anandite is a rarephyllosilicate with formula(Ba,K)(Fe2+,Mg)3(Si,Al,Fe)4O10(S,OH)2. It crystallizes in themonocliniccrystal system. It is black in color with a glassyluster and a near perfect cleavage.[3]
It was first described in 1967[3] for an occurrence in the Wilagedera Prospect of theNorth Western Province ofSri Lanka in bands ofiron ore.[2][4] It has also been found inBig Creek inFresno County and inTrumball Peak inMariposa County, California as well as theSterling Mine inNew Jersey.[2] It was named forAnanda Kentish Coomaraswamy (1877–1947), who was the first director of the Mineral Survey of Ceylon, Sri Lanka.[4]
Anandite is a member of themica group of minerals.[3] Other minerals that anandite is associated with include:magnetite,chalcopyrite,pyrite,pyrrhotite andbaryte.[3]
 | This article about a specificsilicate mineral is astub. You can help Wikipedia byadding missing information. |