Hsianghualite

Hsianghualite
Hsianghualite from the type locality. Specimen size 1.5 cm
General
Category Zeolite
Formula
(repeating unit)		 Li2Ca3(BeSiO4)3F2
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,[1] originally reported as 4 3 2[2]
Identification
Formula mass 475.4 g/mol
Color White or colorless
Crystal habit trisoctahedral or dodecahedral crystals or granular masses[2]
Cleavage None
Tenacity Brittle[3]
Mohs scale hardness 6.5
Luster Vitreous
Streak White
Diaphaneity Transparent to translucent
Specific gravity 2.97 to 3.00, measured[4]
Refractive index n = 1.6132[2]

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.

Structure

Structure is analogous to that of analcime with Be and Si in tetrahedral co-ordination forming a three-dimensional framework.[1] Its space group is I213[1] (Previously reported as I4132[2]). Unit cell parameters are a = 12.879 or 12.897,[2][4] 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.[5] Associated mineral include fluorite, liberite, chrysoberyl, taaffeite and nigerite.[1]

Localities

Hsianghualite has been found only at the type locality, the Xianghualing Mine in Linwu County, Hunan Province, China.

References

  1. 1 2 3 4 Gaines et al (1997) Dana's New Mineralogy Eighth Edition
  2. 1 2 3 4 5 American Mineralogist (1959) 44:1327 English language abstract of Huang Yung-hwei, Tu Shaohua, Wang K'ung-hai, Chao Chun-Lin, and Yu Cheng-Chih (1958)Ti-chih-yueh-k'an 7: 35 (in Chinese)
  3. ↑ http://rruff.geo.arizona.edu/doclib/hom/hsianghualite.pdf
  4. 1 2 American Mineralogist (1961) 46:244. Data from A A Beus (1960) Akademii Nauk SSSR 1-329 (in Russian).
  5. ↑ Roberts, Campbell and Rapp (1990) Encyclopedia of Minerals, 2nd edition
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