Sinjarit
| Sinjarit | |
|---|---|
| General and classification | |
| other names |
IMA 1979-041 |
| chemical formula | CaCl 2 • 2H 2 O |
|
Mineral class (and possibly department) |
Halides |
|
System no. to Strunz and to Dana |
3.BB.25 ( 8th edition : III / A.12) 02/09/05/01 |
| Crystallographic Data | |
| Crystal system | tetragonal |
| Crystal class ; symbol | Please complete |
| Lattice parameters | a = 7.21 Å ; c = 5.86 Å |
| Formula units | Z = 2 |
| Physical Properties | |
| Mohs hardness | 1.5 |
| Density (g / cm 3 ) | 41.66 |
| Cleavage | Well |
| colour | pale pink |
| Line color | White |
| transparency | translucent |
| shine | Glass gloss |
| Crystal optics | |
| Refractive index | n = 1.540 |
| Optical character | uniaxial |
| Other properties | |
| Chemical behavior | well soluble in water |
Sinjarite is a very rarely occurring mineral from the mineral class of halides . It crystallizes in the tetragonal crystal system with the chemical composition CaCl 2 · 2H 2 O, so from a chemical point of view it is a water-containing calcium chloride . The mineral forms elongated or rhombic crystals, as well as granular, massive aggregates of a pale pink color.
properties
The mineral is very hygroscopic and easily dissolves in water (117 g in 100 ml of water at 20 ° C). Its melting point is 172 ° C.
Etymology and history
The mineral was first in 1980 by Zeki A. Aljubouri and Salim M. Aldabbagh in the type locality Sinjar (Sinjar English) near the Sinjar Mountains in Iraq found. It is named after this too.
classification
In the Strunz system , Sinjarit is one of the simple halides. After the 8th edition, it forms a group together with Antarcticite , Bischofite , Eriochalcite , Hydrohalite , Nickelbischofite and Rokühnite . In the 9th edition it forms a separate subgroup of the simple, water-containing halides with a metal to halide ratio of 1: 2.
In the Dana systematics , it forms a separate subgroup of halides without and containing water of crystallization with a ratio of metal to halide of 1: 2.
Education and Locations
Sinjarit formed in a wadi , apparently as precipitation from groundwater .
Only a few sites are known of the very rare mineral. In addition to the type locality, Sinjarit was only found on the island of Bulla in the Caspian Sea in a mud volcano .
Crystal structure
Sinjarit crystallizes in the tetragonal crystal system with the lattice parameters a = 7.21 Å and c = 5.86 Å as well as two formula units per unit cell .
See also
Individual evidence
- ↑ a b c Sinjarite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 67 kB ).
- ↑ ZA Aljubouri and SM Aldabbagh: Sinjarite, a new mineral from Iraq. In: Mineralogical Magazine. 1980, 43, pp. 643-645.
- ^ New Dana Classification of Halide Minerals .
literature
- Zeki A. Aljubouri and Salim M. Aldabbagh: Sinjarite, a new mineral from Iraq. In: Mineralogical Magazine. 1980, 43, pp. 643-645 ( pdf ).