Arsenolamprit
| Arsenolamprit | |
|---|---|
 |
|
| General and classification | |
| other names |
|
| chemical formula | As |
|
Mineral class (and possibly department) |
elements |
|
System no. to Strunz and to Dana |
1.CA.10 ( 8th edition : I / B.01) 03/01/02/01 |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-dipyramidal; 2 / m 2 / m 2 / m |
| Space group | Bmeb (No. 64, position 6) |
| Lattice parameters | a = 3.63 Å ; b = 4.45 Å; c = 10.96 Å |
| Formula units | Z = 8 |
| Physical Properties | |
| Mohs hardness | 2 |
| Density (g / cm 3 ) | measured: 5.3 to 5.5; calculated: 5.577 |
| Cleavage | completely after (001) |
| Break ; Tenacity | not defined |
| colour | initially gray-white, matt black crust due to weathering |
| Line color | black |
| transparency | opaque |
| shine | strong metallic luster |
Arsenolamprite , also known as black arsenic , is a very rarely occurring mineral from the mineral class of the "elements", which chemically consists of pure arsenic , but in contrast to this metastable crystallizes in the orthorhombic crystal system. However, natural arsenolamprite can contain up to 3% bismuth .
Arsenolamprit is opaque and usually develops needle-like or leafy to thick tabular crystals, but also radial or massive mineral aggregates . When fresh, the mineral is initially gray-white and has a strong metallic sheen . However, due to weathering, it gradually becomes coated with a matt black crust.
Etymology and history
The mineral under the name was first mentioned arsenic gloss or arsenic shine in by August Breithaupt published in 1823 the full characteristics of the mineral system , but contains only a brief description of the color and crystal form.
The mineral is not fully described until 1886 by Carl Hintze , who refers, among other things, to samples from the "Palmbaum pit" near Gehringswalde in the Erzgebirgskreis, which were already analyzed by Breithaupt. This is therefore considered to be the first place of discovery for arsenolamprit and thus type locality . Hintze states that this mineral is an allotropic modification similar to that of graphite and diamond and suggests arsenolamprite as a new name, based on its chemistry and its strikingly strong metallic luster ( Greek : λαμπρός [lampros] for shiny ).
classification
In the meanwhile outdated, but still in use 8th edition of the mineral classification according to Strunz , the arsenolamprite belonged to the department of "semimetals and non-metals", where together with antimony , arsenic, bismuth , paradocrasite , pararsenolamprit and stibarsen it forms the "arsenic group" with the System no. I / B.01 formed.
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 classifies arsenol amprite in the category of "semi-metals (metalloids) and non-metals". This is, however, further subdivided according to related element groups, so that the mineral can be found accordingly in the sub-section “arsenic group elements”, where it is only together with pararsenolamprite that the “arsenolamprite group” named after it with the system no. 1.CA.10 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking area , also classifies arsenol amprite in the “element minerals ” department. Here it can also be found together with pararsenolamprite in the unnamed group 01.03.02 within the sub-section " Elements: Semi-Metals and Non-Metals ".
Crystal structure
Arsenolamprit crystallizes orthorhombically in the space group Bmeb (space group no. 64, position 6) with the lattice parameters a = 3.63 Å ; b = 4.45 Å and c = 10.96 Å and 8 formula units per unit cell .
Education and Locations
Arsenolamprit forms hydrothermally on veins as well as in calcite veins (Germany) and veins in carbonate rocks (Czech Republic). As Begleitminerale among other native arsenic, bismuth and can silver , arsenic sulphides orpiment and realgar and as more Sulfides and arsenides Emplectite , galena , Löllingit , pyrite , safflorite and Sternbergit occur.
As a rare mineral formation, arsenolamprite could only be detected at a few sites, whereby so far (as of 2013) around 20 sites are known. In addition to its type locality "Grube Palmbaum", the mineral was also found in Germany in the "Grube Vater Abraham" near Lauta in the Saxon Ore Mountains, in the mines "Sophia", "Johann" and "Anton" near Wittichen in Baden-Württemberg, in the quarry " fox "on the hard Koppe at Sailauf in the Bavarian Spessart Mountains and the amphibolite - quarry in Abtsteinach -Mackenheim and the quarry" Glasberg "in Nieder-Beerbach on in Hesse.
In Austria, arsenolamprit has so far only been found on the zinc wall near Schladming in the Liezen district. A second, but not secured site is the small mine “Samer” near the cadastral community of Kothgraben / Reisstrasse in Styria.
The only previously known site in Switzerland is the "Lengenbach mine" in the Binntal (Canton of Valais).
Other previously known sites are the "Plaka mines" near the Greek community of Lavrio , Alto Ligonha (Muiâne Pegmatite) in the province of Zambezia in Mozambique and the "Screamer" deposit in Eureka County in the US state of Nevada.
Precautions
See also
literature
- C. Hintze : Ueber Arsenolamprit , In: Zeitschrift für Krystallographie und Mineralogie , Volume 11 (1886), pp. 606–608 ( PDF 396.1 kB )
- Hans Jürgen Rösler : Textbook of Mineralogy . 4th revised and expanded edition. German publishing house for basic industry (VEB), Leipzig 1987, ISBN 3-342-00288-3 , p. 285 .
Web links
- Mineral Atlas: Arsenolamprit (Wiki)
- Mindat - Arsenolamprite
- Database-of-Raman-spectroscopy - Arsenolamprite
Individual evidence
- ↑ Webmineral - Arsenolamprite
- ↑ a b The former name of this room group was Bmab .
- ^ A b c 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. 50 .
- ↑ a b Arsenolamprite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 57.1 kB )
- ^ Friedrich Klockmann : Klockmanns textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke , Stuttgart 1978, ISBN 3-432-82986-8 , pp. 403 (first edition: 1891).
- ↑ JFA Breithaupt : Arsenik-Glanz , In: Complete characteristics of the mineral system , 2nd edition, Arnoldische Buchhandlung, Dresden 1823, p. 129 ( PDF 653.4 kB )
- ↑ C. Hintze : Ueber Arsenolamprit , In: Zeitschrift für Krystallographie und Mineralogie , Volume 11 (1886), p. 608 ( PDF 396.1 kB )
- ↑ Mindat - Number of locations for arsenolamprit
- ↑ Find location list for arsenolamprit in the Mineralienatlas and Mindat