Hsianghualite
Zeolite mineral
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Hsianghualite is a tectosilicate (framework silicate) of lithium, calcium and beryllium, with fluorine, a member of the zeolite group. It was discovered in 1958 and named for the type locality, Hsiang Hua, 香花, meaning fragrant flower.
| Hsianghualite | |
|---|---|
Hsianghualite from the type locality. Specimen size 1.5 cm | |
| General | |
| Category | Tectosilicate minerals |
| Group | Zeolite group |
| Formula | Ca3Li2(Be3Si3O12)F2[1] |
| IMA symbol | Hsi[2] |
| Strunz classification | 9.GB.05 (10 ed) 8/J.16-10 (8 ed) |
| Dana classification | 77.1.1.5 |
| Crystal system | Isometric |
| Crystal class | Tetartoidal (23) H-M symbol: (23) |
| Space group | I213,[3] originally reported as 4 3 2[4] |
| Identification | |
| Formula mass | 475.4 g/mol |
| Color | White or colorless |
| Crystal habit | trisoctahedral or dodecahedral crystals or granular masses[4] |
| Cleavage | None |
| Tenacity | Brittle[5] |
| Mohs scale hardness | 6.5 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent to translucent |
| Specific gravity | 2.97 to 3.00, measured[6] |
| Refractive index | n = 1.6132[4] |
Structure
Structure is analogous to that of analcime with Be and Si in tetrahedral co-ordination forming a three-dimensional framework.[3] Its space group is I213[3] (Previously reported as I4132[4]). Unit cell parameters are a = 12.879 or 12.897,[4][6] and Z = 8.
Environment
It occurs within phlogopite veins in the light-coloured band of green and white banded metamorphosed Devonian limestone which has been intruded by beryllium-bearing granite.[7] Associated mineral include fluorite, liberite, chrysoberyl, taaffeite and nigerite.[3]
Localities
Hsianghualite has been found only at the type locality, the Xianghualing Mine in Linwu County, Hunan Province, China.