Glaucokerinite
| Glaucokerinite | |
|---|---|
 |
|
| General and classification | |
| other names |
Copper zinc alumina sulfate |
| chemical formula | [(Zn, Cu, Al) 9 (OH) 18 ] [(SO 4 ) 2 · 10H 2 O] |
|
Mineral class (and possibly department) |
Sulfates (and relatives) |
|
System no. to Strunz and to Dana |
7.DD.35 ( 8th edition : VI / D.08) 04/31/08/01 |
| Crystallographic Data | |
| Crystal system | trigonal |
| Crystal class ; symbol | ditrigonal-scalenohedral; 3 2 / m |
| Space group | R 3 m (No. 166) |
| Lattice parameters | a = 3.06 Å ; c = 32.65 Å |
| Formula units | Z = 1/3 |
| Physical Properties | |
| Mohs hardness | 1 (wax soft) |
| Density (g / cm 3 ) | measured: 2.4 (2); calculated: 2.33 |
| Cleavage | no |
| Break ; Tenacity | not defined |
| colour | sky blue to blue-green, changing to gray or brownish due to contamination |
| Line color | bluish white |
| transparency | translucent |
| shine | Wax gloss |
| Crystal optics | |
| Refractive indices |
n α = 1.540 n β = 1.554 n γ = 1.562 |
| Birefringence | δ = 0.022 |
| Optical character | uniaxial, abnormal biaxial negative |
| Axis angle | 2V = 60 ° (measured); 72 ° (calculated) |
Glaucokerinite , also known as copper-zinc alumina sulfate , is a rarely occurring mineral from the mineral class of " sulfates ( and relatives )". It crystallizes in the trigonal crystal system with the chemical composition [(Zn, Cu, Al) 9 (OH) 18 ] [(SO 4 ) 2 · 10H 2 O], so from a chemical point of view it is a water-containing, basic sulfate. The elements zinc , copper and aluminum indicated in the round brackets can represent each other in the formula ( substitution , diadochie), but are always in the same proportion to the other components of the mineral.
Glaucokerinite develops only microscopic crystals and is mostly found in the form of sky-blue to blue-green banded, grape-like crusts with a radial fibrous to tabular structure and a wax-like sheen on the surfaces. Its hardness is also described as soft as wax, which means that it can be scraped with a fingernail , similar to the reference mineral talc for Mohs hardness 1. It is noticeable that the coloration is always most intense on the surface of the grape vineyards and turns into white on the inside. The color can also turn gray or brown through impurities.
Etymology and history
Glaucokerinite was discovered on various mineral samples from Lavrio ( Laurion ), which the Natural History Museum Vienna in the years 1892 and 1893 by Mrs. Cl. Grenié had acquired. Emil Dittler (1882–1945) and Rudolph Ignatz Koechlin (1862–1939) described the mineral in 1932 and named it due to its color and its waxy consistency after the ancient Greek words γλαυκός [glaukós] with the posthomeric meaning “shiny”, “blue-green” "Or" blue-gray "and κήρινος [kérinos] for wax.
classification
In the meanwhile outdated, but still in use 8th edition of the systematics of minerals according to Strunz , the glaucokerinite belonged to the mineral class of "sulfates, selenates, tellurates, chromates, molybdates, wolframates" and there to the department of "hydrous sulfates with foreign anions ", where he together with Bechererite , Camérolait , carbonate Cyanotrichit , Carrboydit , Chalkoalumit , Cyanotrichit , Hydrombobomkulit , Hydrowoodwardit , Kirgizstanit , Mbobomkulit , Nickelalumit , Spangolith , Woodwardite , Zincowoodwardit and Zinkaluminit the "Cyanotrichit group" with the system number. VI / D.08 .
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also assigns glaucokerinite to the class of "sulfates (selenates, tellurates, chromates, molybdates and tungstates)" and there in the department of "Sulphates (selenates, etc.) with additional anions, with H 2 O". However, this section is further subdivided according to the relative size of the cations involved and the crystal structure, so that the mineral is classified in the sub-section “With only medium-sized cations; Layers of edge-sharing octahedra "can be found, where together with carboydite, honessite , hydrohonessite , hydrowoodwardite, motukoreaite , mountkeithit , natroglaucokerinite , nikischerite , shigaite , vermlandite , woodwardite, zincowoodwardite and zinc aluminite the" woodwardite group "is found. 7.DD.35 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns glaucokerinite to the class of "sulfates, chromates and molybdates" and there to the category of "water-containing sulfates with hydroxyl or halogen". Here it can be found together with natroglaucokerinite in the unnamed group April 31, 2008 within the sub-section " Hydrogen sulfates with hydroxyl or halogen with (A + B2 +) 4 (XO4) Zq × x (H2O)".
Crystal structure
Glaucokerinite crystallizes trigonal in the space group R 3 m (space group no. 166) with the lattice parameters a = 3.06 Å and c = 32.65 Å as well as 1/3 formula units per unit cell .
Education and Locations
Glaucokerinite is formed as a rare secondary mineral in copper-zinc-sulfide deposits . As Begleitminerale occur more sulfate minerals such Ktenasit , Serpierit and plaster , but also among other sulfides such as galena , pyrite and sphalerite and fluorite , Adamin , azurite and malachite , calcite , Smithsonite and limonite limonite .
As a rare mineral formation, glaucoma kerinite has only been found at a few sites so far, with around 15 sites being known (as of 2013). At its type locality Lavrio mineral in various mines or on tailings and slag halden to Agios Konstantinos and Sounion be found. The "Serpieri Mine" is particularly well known for its extraordinarily rich glaucokerinite aggregates.
In Germany, the mineral has so far been found on the slag heaps of the Juliushütte in Lower Saxony as well as the Binsfeldhammer lead smelter and the Münsterbusch zinc smelter in North Rhine-Westphalia, near Kropfmühl in the Bavarian Forest, in the Friedrichssegen mine in Rhineland-Palatinate and in the mine belonging to the fairy grottoes “Jeremias Glück” in Saalfeld, Thuringia.
The only previously known site in Austria is Viehhofen in the Salzburg region.
Other previously known sites are Le Penay in the Vallée de la Tarentaise in France, the “Skyttemyr” pits near Froland ( Aust-Agder ) and “Birkeland” near Sauda (Rogaland) in Norway and the “Maid of Sunshine Mine” in the Dragoon Mountains in Cochise County, Arizona in the USA.
See also
literature
- E. Dittler, R. Koechlin: About Glaukokerinit, a new mineral from Laurion . In: Centralblatt für Mineralogie, Geologie und Paläontologie . tape 1 , 1932, p. 13–17 ( rruff.info [PDF; 269 kB ]).
- Gunnar Raade , CJ Elliott, VK Din: New data on glaucocerinite . In: Mineralogical Magazine . tape 49 , 1985, pp. 583-590 ( rruff.info [PDF; 514 kB ]).
Web links
- Mineral Atlas: Glaucokerinite (Wiki)
- Database-of-Raman-spectroscopy - Glaucocerinite
- Web mineral - glaucokerinite
Individual evidence
- ↑ a b c d Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables. Chemical-structural Mineral Classification System . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 403 .
- ↑ a b Glaucocerinite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 ( handbookofmineralogy.org [PDF; 65 kB ; accessed on October 15, 2017]).
- ↑ a b c d e Mindat - Glaucokerinite
- ^ Herbert Haberlandt: In memory of Emil Dittler . In: Tschermaks mineralogical and petrographic communications . tape 1 , no. 2 , 1948, p. 101-106 , doi : 10.1007 / BF01120828 .
- ↑ Mindat - Number of localities for Glaucocerinite
- ↑ Find location list for glaucokerinite in the Mineralienatlas and Mindat