Rosickýit

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Rosickýit
Rosickýite.jpg
Matrix pale yellow rosickýite crystals from an unnamed borehole in the Pacific Ocean near Ventura County , California
General and classification
other names

Gamma sulfur

chemical formula γ- S
Mineral class
(and possibly department) 		Elements - semi-metals (metalloids) and non-metals
System no. to Strunz
and to Dana 		1.CC.05 ( 8th edition : I / B.03)
03/01/05/02
Crystallographic Data
Crystal system monoclinic
Crystal class ; symbol monoclinic prismatic; 2 / m
Space group P 2 / c (No. 13)Template: room group / 13
Lattice parameters a  = 8.44  Å ; b  = 13.02 Å; c  = 9.36 Å
β  = 125.0 °
Formula units Z  = 32
Frequent crystal faces {010}, {110}, {111}, { 1 11}
Physical Properties
Mohs hardness "Soft" (1 to 2 or 2 to 3)
Density (g / cm 3 ) calculated: 2.02 to 2.03
Cleavage is missing
Break ; Tenacity not defined
colour colorless to light yellow with a greenish tint
Line color White
transparency transparent to translucent
shine Diamond luster

Rosickýite is a rarely occurring mineral from the mineral class of the "elements". It crystallizes in the monoclinic crystal system with the chemical composition γ-S and is therefore the third modification of the chemical element sulfur, alongside the well-known α- sulfur and the equally rare β- sulfur.

Rosickýit only develops microscopic, needle-like to tabular, strip-shaped or dipyramidal crystals up to about one millimeter in length with a diamond-like sheen on the surfaces. But it can also be found in the form of crusts or efflorescence on other minerals or rocks. Rosickýit is usually light yellow in color with a greenish tinge, but it can also be colorless. In contrast, rosickýite with a high selenium content is orange.

Etymology and history

Was first discovered in rosickýite Havírna near Letovice in the Czech Republic and described in 1931 by Josef Sekanina (1901-1986), of the minerals by Vojtěch Rosicky' of Mineralogical-petrological Institute of (1880-1942), the founder and then head Masaryk University , named .

classification

Already in the outdated 8th edition of the mineral classification according to Strunz , the rosickýite belonged to the department of "semi-metals and non-metals", where together with sulfur ( α-sulfur ), β-sulfur , selenium and tellurium it belongs to the "sulfur-selenium group" the system no. I / B.03 formed.

In the last revised and updated Lapis mineral directory by Stefan Weiß in 2018 , which, out of consideration for private collectors and institutional collections, is still based on this classic system of Karl Hugo Strunz , the mineral was given the system and mineral number. I / B.03-20 . In the “Lapis system”, this also corresponds to the “Semi-Metals and Non-Metals” section, where rosickýite, together with sulfur, selenium and tellurium, forms an independent but unnamed group.

The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and was updated by the International Mineralogical Association (IMA) until 2009, also classifies the rosickýite in the category of "semi-metals (metalloids) and non-metals". This is, however, further subdivided according to related element families, so that the mineral can be found accordingly in the sub-section "Sulfur-Selenium-Iodine", where only together with β-sulfur and sulfur the "sulfur group" with the system no . 1.CC.05 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , also assigns the Rosickýit to the class and division of the same name of "elements". Here it is together with sulfur in the " sulfur polymorph " with the system no. 01.03.05 to be found in the sub-section "Elements: Semi-Metals and Non-Metals".

Crystal structure

Rosickýite crystallizes monoclinically in the space group P 2 / c (space group no. 13) with the lattice parameters a  = 8.44  Å ; b  = 13.02 Å; c  = 9.36 Å and β = 125.0 ° and 32 formula units per unit cell . Template: room group / 13

properties

Rosickýite is unstable and slowly converts to α-sulfur at room temperature.

Education and Locations

At its type locality Havírna in the Czech Republic, rosickýite was found in hollow limonite nodules, which were covered by a thin layer of clay. The mineral is also formed directly from volcanic gases that emerge at fumaroles such as the fossa crater on the Italian island of Vulcano . In addition, rosickýite can arise as a conversion product from pyrite-rich asphalt , such as in the former Swiss asphalt plant La Presta in the Val de Travers, or as a conversion product from gypsum and stabilized by microbial activity such as in Death Valley .

As a rare mineral formation, rosickýite could only be detected at a few sites, with around 20 sites being known to date (status 2014). In addition to its type locality Havírna, the mineral also appeared in the Czech Republic near Vísky near Letovice and in the municipality of Kelčany in the Moravia region.

In Germany, rosickyite was found in the Sankt Andreasberg mine area and in the Glücksrad mine near Oberschulenberg in the Harz Mountains in Lower Saxony, in the Marie mine near Wilnsdorf in North Rhine-Westphalia, in the “Virneberg” mine near Rheinbreitbach and “Reichensteinerberg” near Puderbach in Rhineland- Palatinate and in the Lichtenberg opencast mine (formerly Lichtenberg (Kauern) ) in Thuringia.

Other previously known sites include the “Sulfur Bank Mine” near Clear Lake Oaks in Lake County , at Rincon Point near Carpinteria in Santa Barbara County and in an unspecified offshore drill core off the coast of Ventura County in the US state of California ; the sulfur mine "El Desierto" near San Pablo de Napa in the Bolivian province of Daniel Campos (Potosí); the Krafla volcanic complex in Iceland; the ore mines “Adami No. 02 "and" Plaka Mine No. 80 ”near Plaka in the Greek municipality of Lavrio (Attica), the coal mining area of Chelyabinsk in the Russian Urals region and Lake Rotokawa in the Taupo District in New Zealand.

See also

literature

Web links

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

Individual evidence

  1. ^ A b David Barthelmy: Rosickýite Mineral Data. In: webmineral.com. Retrieved November 18, 2019 .
  2. ^ 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.  53 (English).
  3. ^ Helmut Schrätze , Karl-Ludwig Weiner : Mineralogie. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp.  105 .
  4. ↑ a b Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties. Status 03/2018 . 7th, completely revised and supplemented edition. Weise, Munich 2018, ISBN 978-3-921656-83-9 .
  5. ↑ Rosickýite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 (English, handbookofmineralogy.org [PDF; 61  kB ; accessed on November 18, 2019]).
  6. ↑ Orange selenian rosickyite. In: mindat.org. Hudson Institute of Mineralogy, accessed November 18, 2019 .
  7. ↑ Sekanina, Josef. In: Heribert Sturm, Ferdinand Seibt, Hans Lemberg, Helmut Slapnicka (eds.): Biographical lexicon for the history of the Bohemian countries. Oldenbourg Verlag, 2003, p. 38 ( available online in the Google book search)
  8. ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed November 18, 2019 .
  9. ↑ 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.  294 .
  10. ↑ Localities for Rosickýite. In: mindat.org. Hudson Institute of Mineralogy, accessed November 18, 2019 .
  11. ↑ Find location list for rosickýite in the Mineralienatlas and Mindat , accessed on November 18, 2019.