Coccinite
| Coccinite | |
|---|---|
 |
|
| General and classification | |
| other names |
|
| chemical formula | Hg 2+ I 2 |
|
Mineral class (and possibly department) |
Simple halides |
|
System no. to Strunz and to Dana |
3.AB.10 ( 8th edition : III / A.08) 02/09/07/03 |
| Crystallographic Data | |
| Crystal system | tetragonal |
| Crystal class ; symbol | ditetragonal-dipyramidal; 4 / m 2 / m 2 / m |
| Space group | P 4 2 / nmc (No. 137) |
| Lattice parameters | a = 4.38 Å ; c = 12.41 Å |
| Formula units | Z = 2 |
| Physical Properties | |
| Mohs hardness | 2 |
| Density (g / cm 3 ) | 6.36 |
| Cleavage | Well |
| colour | orange, scarlet, brown |
| Line color | Orange red |
| transparency | translucent |
| shine | Please complete |
| Other properties | |
| Special features | very poisonus |
Coccinite is a very rarely occurring mineral from the mineral class of halides . It crystallizes in the tetragonal crystal system with the composition Hg 2+ I 2 , so it is chemically a mercury (II) iodide .
Coccinite only develops millimeter-sized crystals and powdery coatings or crusts of scarlet red or orange-red to brown in color with orange-red streak color .
Etymology and history
Coccinite was first discovered at Casas Viejas in Mexico and described by Del Rio in 1829 as Iodure de Mercure (German: Iodmercur or Iodmercury or Mercury iodide).
The name of the mineral , which is still valid today, was given in 1845 by Wilhelm von Haidinger , who named it after the Latin word coccineus for "scarlet" based on its color .
classification
In the now outdated, but still in use 8th edition of the mineral classification according to Strunz , the coccinite belonged to the department of "simple halides", where together with fluorite , frankdicksonite , gagarinite- (Y) , gagarinite- (Ce) (formerly zajacite- ( Ce) ), Håleniusit- (La) , Laurelite and Tveitit- (Y) the "Fluorite series" with the system no. III / A.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), classifies coccinite in the newly defined division of "Simple halides without H 2 O". This department is further subdivided according to the molar ratio of metal (M) to halide (X) involved, so that the mineral can be found in the subdivision "M: X = 1: 2" according to its composition, where it is the only member unnamed group forms 3.AB.10 .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns coccinite to the “halides” division. Here it is together with cotunnite and hydrophilite in the "cotunnite group" with the system no. 02/09/07 to be found in the subsection of " Anhydrous and hydrous halides with the formula AX 2 ".
Crystal structure
Coccinite crystallizes in the tetragonal crystal system in the space group P 4 2 / nmc (space group no. 137) with the lattice parameters a = 4.38 Å and c = 12.41 Å as well as 2 formula units per unit cell .
properties
The mineral is very toxic, so direct contact should be avoided if possible.
Education and Locations
Due to its rarity, no more precise statements could be made about the formation conditions of coccinite.
So far (as of 2012) the mineral was found at its type locality Casas Viejas in Mexico at Broken Hill (New South Wales) in Australia as well as in the pits "Ofen" and "Carolina" at Moschellandsberg (Rhineland-Palatinate) and in the open pit Lichtenberg (Thuringia, see also description of deposits at Wismut AG ) discovered in Germany.
Web links
- Mineral Atlas: Coccinite (Wiki)
- Thomas Witzke : Mineral Photo Atlas - Coccinit at www.strahl.org
- Mindat - Coccinite
Individual evidence
- ↑ a b c indra-g.at: Old mineral names and synonyms (PDF 2.65 MB)
- ↑ Webmineral - Coccinite (English)
- ^ A b c 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. 152 .
- ^ Carl Friedrich Naumann: Elements of Mineralogy . W. Engelmann, 1859. ( Book in Google book search)
- ↑ archive.org: A dictionary of the names of minerals including their history and etymology by Albert Huntington Chester, New York, London 1896
- ↑ Find location list for coccinite in the Mineralienatlas and Mindat