Trögerit
| Trögerit | |
|---|---|
 |
|
| General and classification | |
| chemical formula |
|
|
Mineral class (and possibly department) |
Phosphates, arsenates and vanadates |
|
System no. to Strunz and to Dana |
8.EB.15 ( 8th edition : VII / E.01) 40.02a.20.01 |
| Crystallographic Data | |
| Crystal system | tetragonal |
| Crystal class ; symbol | 4 / mmm |
| Space group | P 4 / nmm (No. 129) |
| Lattice parameters | a = 7.16 Å ; c = 8.80 Å |
| Formula units | Z = 1 |
| Frequent crystal faces | tabular along {001} |
| Physical Properties | |
| Mohs hardness | 2 to 3 |
| Density (g / cm 3 ) | measured: 3.3; calculated: [5.13] |
| Cleavage | perfect after {001}, good after {100} |
| Break ; Tenacity | micaceous |
| colour | lemon yellow |
| Line color | pale yellow |
| transparency | transparent |
| shine | Pearlescent |
| radioactivity | 88.4 k Bq / g |
| Crystal optics | |
| Refractive indices |
n ω = 1.624 to 1.627 n ε = 1.580 to 1.582 |
| Birefringence | δ = 0.040 |
| Optical character | uniaxial negative |
| Axis angle | 2V = 0 to 40 ° |
| Other properties | |
| Special features | toxic |
Trögerite is a very rarely occurring mineral from the mineral class of "phosphates, arsenates and vanadates" with the chemical formula (H 3 O) 2 [UO 2 | AsO 4 ] 2 · 6–8H 2 O and is therefore chemically a water-containing oxonium - uranyl - arsenate .
Trögerite crystallizes in the tetragonal crystal system and develops thin tabular, mica-like crystals of lemon yellow color, which can be up to a millimeter in size.
Etymology and history
The mineral was first discovered in the Weißer Hirsch mine in Schneeberg in the Ore Mountains ( Saxony ) in 1871 by the mining officer R. Tröger. It was then described by Albin Weisbach , who named it after Tröger. Together with the Trögerite, he also discovered the mineral walpurgin , named after the Walpurgis corridor in which the discovery was made within the mine.
classification
Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the Trögerite belonged to the mineral class of "Phosphate, Arsenate and Vanadate" and there to the department of "Uranylphosphate / Arsenate and Uranylvanadate", where it together with Autunit , Fritzscheit , Heinrichit , Kahlerit , Nováčekit , Torbernit , Sabugalit , Saléeit , Uranocircit , Uranospinit , Zeunerit the "Autunit Group" with the system no. VII / E.01 .
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 Trögerite in the category of “uranyl phosphates and arsenates”. However, this is further subdivided according to the molar ratio of the uranyl groups to the phosphate, arsenate or vanadate complex, so that the mineral is classified according to its composition in the subdivision "UO 2 : RO 4 = 1: 1, Autunit family: [(UO 2 ) -RO 4 ] layers ”, where it forms the unnamed group 8.EB.15 together with abernathyite , chernikovite , meta-ankoleit , natrouranospinite , uramarsite and uramphite .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns Trögerite to the class of "phosphates, arsenates and vanadates" and there in the department of "water-containing phosphates etc.". Here he is the only member of the unnamed group 40.02a.20 within the subdivision "Water-containing phosphates etc., with A 2+ (B 2+ ) 2 (XO 4 ) × x (H 2 O), with (UO 2 ) 2+ ”can be found.
Crystal structure
Trögerite crystallizes tetragonally in the space group P 4 / nmm (space group no. 129) with the lattice parameters a = 7.16 Å and c = 8.80 Å as well as one formula unit per unit cell .
properties
Trögerite contains chemically bound arsenic and uranium and is therefore highly toxic and carcinogenic . With its uranium content of up to 49.4%, the mineral is also radioactive . Taking into account the natural decay series or any decay products present, the specific activity is given as 88.4 k Bq / g (for comparison: natural potassium 31.2 Bq / g).
The mineral fluoresces lemon yellow under UV light . The content of crystal water is variable and it can be released reversibly .
Education and Locations
Trögerite forms as a secondary mineral in the oxidation zone of some uranium deposits. It is depending on the location associated with Walpurgin, Uranospinit , Uranospathit , Asselbornit , Zeunerit , Uranosphärit and Erythrin in the type locality or realgar , Auripigment , scorodite , Mansfieldit , sodium Uranospinit , Arseniosiderit , Metatorbernit , Metazeunerit , Uranophan , arsenopyrite , pyrite and galena on Alakol lake in Kazakhstan .
Only a small number of places where the Trögerite was found are known (20, as of May 2010). In addition to the type locality, these include Sandon in British Columbia ( Canada ), Příbram , Jáchymov , Harrachov and Javorník in the Czech Republic , Lodève in France , Johanngeorgenstadt and Ronneburg (Thuringia) in Germany , Lake Alakol in Kazakhstan, Prakovce in Slovakia and the US - States of Oregon , South Dakota and Wyoming .
Precautions
Due to the high level of radioactivity and toxicity , mineral samples from Trögerit should only be kept in dust- and radiation-tight containers, but especially never in living rooms, bedrooms or workrooms. Absorption into the body (incorporation, ingestion ) should also be prevented in any case and, for safety, direct body contact should be avoided and respiratory protection mask and gloves should be worn when handling the mineral .
See also
literature
- Albin Weisbach : Preliminary communication [About Trögerite and Walpurgin] . In: New Yearbook for Mineralogy, Geology and Paleontology . 1871, p. 869-870 ( strahlen.org [PDF; 191 kB ; accessed on December 30, 2016]).
- Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 655 (first edition: 1891).
- 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. 651 .
Web links
- Mineral Atlas: Trögerite (Wiki)
Individual evidence
- ↑ a b Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties . 6th, completely reworked and supplemented edition. Weise, Munich 2014, ISBN 978-3-921656-80-8 .
- ^ IMA / CNMNC List of Mineral Names ; November 2015 (PDF; 1.6 MB)
- ^ 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. 526 .
- ↑ a b c d e f g h Trögerite . 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; 67 kB ; accessed on May 21, 2017]).
- ↑ a b Webmineral - Trögerite
- ↑ Mindat - Trögerite
- ^ Albin Weisbach : Preliminary communication [About Trögerit and Walpurgin] . In: New Yearbook for Mineralogy, Geology and Paleontology . 1871, p. 869-870 ( strahlen.org [PDF; 191 kB ; accessed on December 30, 2016]).
- ↑ Find location list for Trögerite in the Mineralienatlas and Mindat