Moschelite

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Moschelite
Moschelite - Oven Pit, Moschellandsberg, 1984 a.jpg
Moschelite in lemon-yellow plates measuring 0.3 mm on cinnabar (red) or in the border of genuine mercury from the oven pit, Moschellandsberg
General and classification
other names

IMA 1987-038

chemical formula
  • HgI
  • Hg 2 I 2
Mineral class
(and possibly department) 		Halides
System no. to Strunz
and to Dana 		3.AA.30 ( 8th edition : III / A.05)
01/09/08/03
Crystallographic Data
Crystal system tetragonal
Crystal class ; symbol ditetragonal-dipyramidal; 4 / m  2 / m  2 / m
Space group I 4 / mmm (No. 139)Template: room group / 139
Lattice parameters a  = 4.8974  Å ; c  = 11.649 Å
Formula units Z  = 2
Physical Properties
Mohs hardness 1 to 2
Density (g / cm 3 ) calculated: 7.75
Cleavage imperfect
Break ; Tenacity clamshell; can be cut with a knife
colour lemon yellow, olive green
Line color brown
transparency opaque, translucent edges
shine Diamond luster

Moschelite is a very rarely occurring mineral from the mineral class of " halides " with the chemical composition Hg 2 I 2 or HgI and thus, chemically speaking, mercury (I) iodide .

Moschelite crystallizes in the tetragonal crystal system , but develops only very small crystals up to about 0.1 mm in size with a tabular to short prismatic habit and a diamond-like sheen on the surfaces. The mineral is usually found in the form of flat aggregates or crusty coatings.

The mineral is generally opaque and only translucent along thin edges. Fresh samples are lemon yellow in color, which, however, quickly changes to dark olive green in the light. The line color , however, is always brown. With a Mohs hardness of 1 to 2, moschelite is one of the soft minerals that, like the reference minerals talc (hardness 1) and gypsum (hardness 2), can be scratched with a fingernail.

Etymology and history

Was first discovered in 1984 by the employees of the Moschelit Pollichia Museum and private researchers Ulrich Heidtke in medieval and probably already ancient mercury - and silver ore - mine "oven" on the Moschellandsberg in Obermoschel in Rhineland-Palatinate ( Germany ). In a small cavity of a pear-shaped chunk of chert , he found, in addition to genuine mercury and some cinnabarite ( vermilion ), a few orange-colored grains and lemon-yellow flakes. In addition, there was an intense odor of iodine . The chemical analysis revealed that the orange-colored grains were coccinite and the yellow platelets were a previously unknown compound of mercury and iodine.

The newly discovered mineral was completely analyzed and described by ER Krupp, G. Nottes and Ulrich Heidtke, who named it after its type locality . The analysis results and the chosen name were submitted for examination to the International Mineralogical Association (IMA accession number : 1987-038 ), which recognized the mineral as an independent mineral species. The first description was published in 1989 in the scientific magazine Neues Jahrbuch für Mineralogie, monthly issues .

Type material for moschelite is found in the collection of the Natural History Museum Vienna (NHMW) under catalog no. M549 kept.

classification

Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the moschelite belonged to the mineral class of the "halides" and there to the department of the "simple halides", where together with calomel and kuzminit he created the "calomel series" with the System no. III / A.05 .

The 9th edition of Strunz's mineral systematics, which has been in force since 2001 and is used by the IMA, classifies moschelite in the more finely subdivided section “Simple halides without H 2 O”. This is further subdivided according to the molar ratio of metal to halide, so that the mineral according to its composition can be found in the sub-section "M: X = 1: 1 and 2: 3", where it is also together with calomel and kuzminit the " Calomel group “ 3.AA.30 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the moschelite to the class and there in the division of the same name of "halides". Here he is also in the " calomel group " with the system no. 09.01.08 to be found in the subsection “Anhydrous and water-containing halides with the formula AX”.

Crystal structure

Crystal structure of moschelite.
__ Hg     __ I

Moschelite crystallizes tetragonally in the space group I 4 / mmm (space group no. 139) with lattice parameters a  = 4.8974  Å and c  = 11.649 Å as well as two formula units per unit cell . Template: room group / 139

Education and Locations

Moschelit formed in one of sandstone surrounded mercury - deposit . The iodide probably comes from an underlying coal seam . In addition to native mercury and the mercury minerals cinnabarite , eglestonite , calomel , metacinnabarite and terlinguaite , aragonite , azurite , gypsum , lepidocrocite , malachite , quartz , various iron oxides and tetrahedrite can occur as accompanying minerals .

In addition to its type locality Moschellandsberg near Obermoschel, only the Mina El Entredicho near Almadenejos in the Almadén mining area in the Spanish province of Ciudad Real is known.

See also

literature

  • R. Krupp, G. Nottes, Ulrich Heidtke: Naturally occurring halogen compounds, especially mercury iodide, from Moschellandsberg, Pfalz, West Germany . In: The opening . tape 36 , 1985, pp. 73-80 .
  • ER Krupp, G. Nottes, Ulrich Heidtke: Moschelite (Hg 2 J 2 ): a new mercury mineral from Landsberg-Obermoschel . In: New yearbook for mineralogy, monthly books . 1989, p. 524-526 .
  • John L. Jambor, Jacek Puziewicz Volume: New Mineral Names . In: American Mineralogist . tape 75 , 1990, pp. 1209–1216 ( rruff.info [PDF; 1.4 MB ; accessed on May 7, 2018]).
  • Walter Bäuml, Ulrich Heidtke: How the Moschellandsberg got new honors . Private researcher discovers new mineral "moschelite" worldwide. In: Donnersberg yearbook . tape 25 , 2002, pp. 165–167 ( Bibliography Rhineland-Palatinate [accessed on May 7, 2018]).
  • Mohammed Kars, Thierry Roisnel, Vincent Dorcet, Allaoua Rebbaha and Otero-Diáz L. Carlos: Redetermination of Hg 2 I 2 . In: Acta Crystallographica Section E . tape 8 , no. February 2 , 2012, doi : 10.1107 / S1600536811056339 .

Web links

Commons : Moschelite  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b c IMA / CNMNC List of Mineral Names; March 2018 (PDF 1.65 MB)
  2. ^ A b 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.  151 .
  3. ^ A b Mohammed Kars, Thierry Roisnel, Vincent Dorcet, Allaoua Rebbaha and Otero-Diáz L. Carlos: Redetermination of Hg 2 I 2 . In: Acta Crystallographica Section E . tape 8 , no. February 2 , 2012, doi : 10.1107 / S1600536811056339 .
  4. ↑ a b c d e f Moschelite . 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]).
  5. ↑ Ulrich HJ Heidtke: Mineralogical rarities in the Palatinate: Moschellandsbergit , in: Reports from the working groups , Pollichia-Kurier 21 (2) 2005, pp. 5-7
  6. ↑ Type locality Grube Ofen at the Mineralienatlas and at Mindat
  7. ↑ Walter Bäuml, Ulrich Heidtke: How the Moschellandsberg got new honors . Private researcher discovers new mineral "moschelite" worldwide. In: Donnersberg yearbook . tape 25 , 2002, pp. 166–167 ( Bibliography Rhineland-Palatinate Bibliography [accessed on May 7, 2018]).
  8. ↑ Catalog of Type Mineral Specimens - M. (PDF 124 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, p. 23 , accessed August 29, 2019 .
  9. ↑ Find location list for moschelite in the Mineralienatlas and Mindat