The crystal structure of gearksutite, CaAlF4(OH)•H2O

被引：7

作者：

Marchetti, F

Perchiazzi, N

机构：

[1] Univ Rome La Sapienza, Dipartimento Ingn Chim Mat Mat Prime & Met, I-00195 Rome, Italy

[2] Univ Pisa, Dipartimento Sci Terra, I-56126 Pisa, Italy

来源：

AMERICAN MINERALOGIST | 2000年 / 85卷 / 01期

关键词：

D O I：

10.2138/am-2000-0123

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

The discovery of unusually well-crystallized samples of gearksutite allowed determination of its crystal structure. The crystals belong to space group P (1) over bar, a = 4.940(1), b = 6.810(1), c = 6.978(1) Angstrom; alpha = 101.12(1), beta = 94.86(1), gamma = 110.07(1)degrees; V = 213.43(6) Angstrom(3); Z = 2. The structure consists of layers of eightfold-coordinated calcium polyhedra connected through pairs of [Al2F8(OH)(2)] octahedra which are oriented identically, similar to those observed in other hydroxyl aluminum fluorides. A comparison with other minerals of similar composition is made. The structure data allowed us to reliably index the powder pattern and to show that the reflection intensities are strongly affected by preferred orientation.

引用

页码：231 / 235

页数：5

共 17 条

[1] THE STRUCTURE OF ACUMINITE, A STRONTIUM ALUMINUM FLUORIDE MINERAL [J].