Niedermayrit
| Niedermayrit | |
|---|---|
 |
|
| General and classification | |
| other names |
IMA 1997-024 |
| chemical formula | CdCu 4 [(OH) 6 | (SO 4 ) 2 ] • 4H 2 O |
|
Mineral class (and possibly department) |
hydrous sulphates with foreign anions |
|
System no. to Strunz and to Dana |
7.DD.30 ( 8th edition : VI / D.19) 06/31/06/02 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Space group | P 2 1 / m (No. 11) |
| Lattice parameters |
a = 5.543 Å ; b = 21.995 Å; c = 6.079 Å β = 92.04 ° |
| Formula units | Z = 2 |
| Physical Properties | |
| Mohs hardness | 2 to 3 |
| Density (g / cm 3 ) | 3.36 |
| Cleavage | completely along {010} |
| Break ; Tenacity | brittle |
| colour | bluish green |
| Line color | White |
| transparency | transparent |
| shine | Glass gloss |
| Crystal optics | |
| Refractive indices |
n α = 1.599 to 1.619 n β = 1.642 n γ = 1.661 |
| Birefringence | δ = 0.062 |
| Optical character | biaxial negative |
| Axis angle | 2V = 84 ° |
Niedermayrit is a very rarely occurring mineral from the mineral class of water-containing sulfates with foreign anions. It crystallizes in the monoclinic crystal system with the chemical composition CdCu 4 [(OH) 6 | (SO 4 ) 2 ] · 4H 2 O and usually develops massive aggregates and crusty coatings in blue-green color.
Etymology and history
Niedermayrit was first found in 1995 by F. Schreiber in the type locality in the mining area of Laurion in Greece and described by G. Giester, B. Rieck and F. Brandstätter. They named it after the Austrian mineralogist and curator of the mineralogical collection of the Natural History Museum Vienna Gerhard Niedermayr (1941–2015).
classification
In the old (8th edition) and new systematics of minerals according to Strunz (9th edition) , the Niedermayrit belongs to the department of "Water-containing sulfates with foreign anions ". The new Strunz'sche mineral system, however, subdivides here more precisely according to the size of the cations involved and the mineral is therefore now correspondingly in the subdivision "with medium-sized cations and edge-linked octahedra", where it is group 7 with campigliaite , devillin , lautenthalite , orthoserpierite and serpierite .DD.30 forms.
The systematics of minerals according to Dana , which is common in the English-speaking world , also assigns the Niedermayrit to the sulphate class, but there in the category of " water-containing sulphates with hydroxyl and halogen groups with the general formula (A + B 2+ ) 5 (XO 4 )" 2 Z q × x (H 2 O) “, where he and Campigliait form the unnamed group 06/31/06 .
Crystal structure
Niedermayrit crystallizes in the monoclinic crystal system in the space group P2 1 / m with the lattice parameters a = 5.543 Å ; b = 21.995 Å; c = 6.079 Å and β = 92.04 ° as well as two formula units per unit cell .
properties
When heated, the mineral loses its in two stages at about 100 to 300 ° C water of crystallization .
Education and Locations
Niedermayrite is probably formed as a secondary mineral as an aging product of greenockite and chalcopyrite . The matrix consists of marble interspersed with sphalerite , chalcopyrite, galena , greenockite, hawleyite and pyrite . Other minerals with which Niedermayrit is associated are the secondary minerals gypsum , malachite , chalcanthite , brochantite , hemimorphite , hydrozincite , aurichalcite , monteponite and otavite .
So far, only a few places where Niedermayrit was found are known. These are several pits at Laurion in Greece, the Hidden Treasure Mine at Ophir in the US state of Utah as well as the Broken Hill deposit in the Australian state of New South Wales and a locality in Bolivia.
See also
literature
- G. Giester, B. Rieck, F. Brandstätter: Niedermayrite, Cu 4 Cd (SO 4 ) 2 (OH) 6 • 4H 2 O, a new mineral from the Lavrion Mining District, Greece . In: Mineralogy and Petrology . 1998, 63, pp. 19-34, doi : 10.1007 / BF01162766 .
Web links
- Mineral Atlas: Niedermayrit (Wiki)
- Mindat - Niedermayrite (English)
- Webmineral - Niedermayrite (English)