Odinite
| Odinite | |
|---|---|
| General and classification | |
| other names |
|
| chemical formula | (Fe 2+ Mg, Al) 5 [(OH) 8 | (Si, Al) 4 O 10 ] |
|
Mineral class (and possibly department) |
Silicates and Germanates |
|
System no. to Strunz and to Dana |
9.EC.55 ( 8th edition : VIII / H.26) 01.01.05 |
| Similar minerals | Allophane, sturtite |
| Crystallographic Data | |
| Crystal system | Odinit-1M: monoclinic; Odinite-1T: trigonal |
| Crystal class ; symbol | Odinit-1M: monoclinic; m Odinit-1T: presumably ditrigonal-pyramidal; 3 / m |
| Space group | see crystal structure |
| Lattice parameters | see crystal structure |
| Formula units | see crystal structure |
| Physical Properties | |
| Mohs hardness | 2.3 to 2.6 |
| Density (g / cm 3 ) | calculated: 2.78 |
| Cleavage | Well |
| Break ; Tenacity | shell-like |
| colour | light green to dark green |
| Line color | gray-green |
| transparency | opaque |
| shine | Silky to earthy |
Odinite is a very rare mineral from the mineral class of silicates and germanates . It crystallizes polytype in the monoclinic crystal system ( Odinit-1M ) and in the trigonal crystal system ( Odinit-1T ) with the chemical composition (Fe 2+ Mg, Al) 5 [(OH) 8 | (Si, Al) 4 O 10 ] and became so far only found in the form of cryptocrystalline aggregates from light green to dark green in color.
Etymology and history
Was found for the first time Odinit 1988 Los Archipelago (Los Islands), a ring-shaped archipelago km about 5 off the coast of Guinea and described by SW Bailey, of the mineral in honor of the French mineralogist Gilles Serge Odin and employees of the University Pierre and Marie Curie named who examined the mineral for the first time.
classification
In the old (8th edition) and new classification of minerals by Strunz (9th edition) of Odinit is part of the Department of phyllosilicates (phyllosilicates). The new Strunz'sche mineral systematics is, however, more precisely subdivided according to the inner structure of the silicate layers and the odinite is found accordingly in the subdivision of "phyllosilicates with kaolinite layers, composed of tetrahedral or octahedral nets", where it is found together with thickite , kaolinite and Nakrit forms the unnamed group 9.ED.05 .
The systematics of minerals according to Dana , which is common in the English-speaking world , also assigns odinite to the layered silicate department, but there in the sub-department of layered silicates with layers of six-membered rings with 1: 1 layers , where it is combined with dickite, kaolinite, halloysite and endellite the "kaolinite group" with the system no. 71.1.1 forms.
Education and Locations
Odinite forms in sea water as a small part of the mixture sprinkled in green clay . Accompanying minerals include calcite , various chlorites , illite , kaolinite, quartz and smectite .
Worldwide, Odinite could so far (as of 2010) be detected only at Nouméa in New Caledonia, apart from its type locality Los Archipelago in Guinea .
Crystal structure
Odinit crystallizes polytype, that is, it forms alternating layers with monoclinic and trigonal symmetry, which are called "Odinit-1M" and "Odinit-1T".
Odinit-1M crystallizes monoclinically in the space group Cm with the lattice parameters a = 5.37 Å ; b = 9.32 Å; c = 7.36 Å and β = 103.9 ° as well as one formula unit per unit cell .
Odinit-1T crystallizes trigonal in the space group P 3 1 m with the lattice parameters a = 5.37 Å and c = 7.16 Å as well as 0.5 formula units per unit cell .
See also
Individual evidence
- ↑ a b c d Hugo Strunz , Ernest H. Nickel: Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 675 .
- ↑ a b c d Handbook of Mineralogy - Odinite (English, PDF 77.5 kB)
- ↑ Mindat - Odinite (English)
Web links
- Mineral Atlas: Odinite (Wiki)
- Webmineral - Odinite (English)
Category: Silicon Mineral