Hsianghualite |Li2 Ca3 F2| [Be3Si3O12]
  Crystals have the appearance of analcime, dodecahedra, to 9 mm, and massive.  
Physical properties:  
  Cleavage: none.
Hardness:  6.5.
D = 2.97 – 3.00 gm/cm3 (meas),
Luster: vitreous.
Streak: white.
Optical properties:            
  Color: colorless; colorless in thin section.
Isotropic  n = 1.6130
  Unit cell data:
a  12.897 Å.
Z = 8,  Space group I213  (Rastsvetaeva et al. 1991).
  Hsianghualite was named by Wen-hui Huang et al. (1958) for a mineral occurring with phlogopite in veins cutting metamorphosed Devonian limestone at Hsianghualing in the Nanling Range, Linwu County, Hunan Provence, China. The name is for the type locality.
Crystal structure:  
  The structure of hsianghualite was determined by Section of Crystal Structure Analysis (1973) and was redetermined and refined by Rastsvetaeva et al. (1991). The framework topology is basically the same as that for analcime, but is somewhat distorted. With alternating Be and Si tetrahedra, the framework has a much greater negative charge than analcime, and the extra-framework cations that balance this charge partially collapse the structure, reducing the cell edge from 13.7 Å in analcime to 12.86 Å.
  Where chains of singly connected 4-rings wrap around screw tetrads in analcime, in hsianghualite the chains wrap around screw diads.
In order to balance the framework charge, all three of the Na-sites of analcime are filled with Ca2+ (green), and the W-sites (H2O) of analcime are occupied by F- (pink) anions. In the distorted cage the Ca positions have been shifted to allow room for another cation, Li. Each Ca is 8-fold coordinated with two F and six oxygens, and each Li (purple) is coordinated with one F and three oxygens.
The partially collapsed unit cell and extra cation occupancy account for the high density, refractive index, and hardness of hsianghualite.
Chemical composition:
  Although Wen-Hui Huang et al. (1958) provided the essential analysis of hsianghualite with their description of the mineral, Beus (1960) published the same analysis and included minor elements along with a second full analysis. Both analyses yield good charge balances, but the first yields cell contents in better agreement with the structure determination.
  Hsianghualite occurs in phlogopite veins in the light-colored band of green and white banded fluorine-rich metamorphosed Devonian limestone intruded by Be-bearing granite. Fluid inclusion work by Liu and Zeng (1998) gives conditions of formation of the veins as 270-290°C and 30 to 60 MPa.
  Beus, A.A. 1960. Geochemistry of beryllium and the genetic types of beryllium deposits. Akad. Nauk SSSR, Inst. Mineral., geokim., I kristollakhim redikh elementov 329 pp. (See Am. Mineral. 46, 244 for abstract of p. 60-61 pertaining to hsianghualite.)

Liu Jiaqi and Zeng Yishan 1998. Preliminary study on fluid inclusions in hsianghualite. Huanan Dizhi Yu Kuangchan 1998, 56-63.

Rastsvetaeva, R.K., Rekhlova, O.Yu., Andrianov, V.I. and Malinovskii, Yu.A. 1991. Crystal structure of hsianghualite. Sov. Phys., Doklady 36, 11-13.

Section of Crystal Structure Analysis, Academy of Geological Science (1973). The crystal structure of hsianghualite. Acta Geologica Sinica 2, 226-242

Wen-Hui Huang, Shao-Hua Tu, K’ung-Hai Wang, Chun-Lin Chao and Cheng-Chih Yu 1958. Hsiang‑hua‑shih [hsianghualite], a new beryllium mineral. Ti‑chih‑yeuh‑k’an 7, 35. (See Am. Mineral. 44, 1327-1328 for abstract.).