God lobite

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God lobite
Gottlobite - Glückstern mine, Gottlob, Thuringia.jpg
Gottlobite (orange) from the "Glückstern Pit", Gottlob, Thuringia
General and classification
other names

IMA 1998-066

chemical formula
  • CaMg (VO 4 ) (OH)
  • CaMg [OH | (VO 4 , AsO 4 )]
Mineral class
(and possibly department) 		Phosphates, arsenates, vanadates
System no. to Strunz
and to Dana 		8.BH.35
05.41.01.10
Crystallographic Data
Crystal system orthorhombic
Crystal class ; symbol orthorhombic-disphenoidic; 222
Space group P 2 1 2 1 2 1 (No. 19)Template: room group / 19
Lattice parameters a  = 7.50  Å ; b  = 9.01 Å; c  = 5.94 Å
Formula units Z  = 4
Frequent crystal faces {010}, {110}, {011}
Physical Properties
Mohs hardness 4.5
Density (g / cm 3 ) calculated: 3.41 and 3.58
Cleavage not visible
Break ; Tenacity shell-like, brittle
colour orange to orange-brown
Line color light brownish white
transparency transparent to translucent
shine Glass gloss to diamond gloss
Crystal optics
Refractive indices n α  = 1.797
n β  = 1.805 to 1.815
n γ  = 1.828
Birefringence δ = 0.031
Optical character biaxial negative
Axis angle 2V = calculated: 62 to 80 °
Pleochroism clear: X = orange brown, Y = pale yellowish brown, Z = orange brown

Gottlobite is a very rarely occurring mineral from the mineral class of " phosphates , arsenates and vanadates ". It crystallizes in the orthorhombic crystal system with the chemical composition CaMg [OH | (VO 4 , AsO 4 )] or CaMg (VO 4 , AsO 4 ) (OH) and usually develops orange to orange-brown, tabular crystals or mineral aggregates with ingrown, isometric grains up to about 0.5 mm in size.

Etymology and history

Gottlobit was discovered in August 1996 by J. Graf on the dump of the disused "Grube Glücksstern" at Gottlob near Friedrichroda in Thuringia.

Gottlobit was scientifically described and named after its type locality in 1998 by Thomas Witzke , Manfred Steins , Thomas Doering and Uwe Kolitsch , who submitted their results and the chosen name to the International Mineralogical Association (IMA) in December of the same year for examination of the mineral status. The application received the entry number IMA 1998-066 and in March 1999 gottlobite was recognized as an independent mineral. The research results and the recognized name were published in 2000 in the monthly journal of the “New Yearbook for Mineralogy”.

The type material (holotype) of the mineral is stored in the geoscientific collections of the TU Bergakademie Freiberg under the collection no. 78907 kept at location c 7.7 .

classification

Since the gottlobite was only recognized as an independent mineral in 1998, it is not yet listed in the 8th edition of the mineral classification according to Strunz , which has been outdated since 1977 . Only Lapis mineral directory according to Stefan Weiß, which is still based on this classic system of Karl Hugo Strunz out of consideration for private collectors and institutional collections , the mineral received the system and mineral number. VII / B.26-15 . In the "lapis system" this corresponds to the class of "phosphates, arsenates and vanadates" and there the department "anhydrous phosphates, with foreign anions F, Cl, O, OH", where gottlobite together with adelite , austinite , fragranceite , gabrielsonite , Hermannroseit , Cobaltaustinit ( Kobaltaustinit ) Konichalcit , Nickelaustinit and Tangeite the "adelite group" formed (as 2018).

The 9th edition of Strunz's mineral systematics, valid since 2001 and updated by the International Mineralogical Association (IMA) until 2009, also assigns gottlobite to the category of “phosphates, etc. with additional anions; without H 2 O “. However, this is further subdivided according to the relative size of the cations involved and the ratio of the additional anions to the phosphate, vanadate or arsenate complex, so that the mineral is classified according to its composition in the sub-section “with medium-sized and mostly large cations; (OH etc.): RO 4  = 1: 1 “can be found, where together with Adelite, Arsendescloizit , Austinite, Cobaltaustinite, Duftite, Gabrielsonite, Konichalcite, Nickelaustinite, Tangeit the“ Adelite group ”with the system no. 8.BH.35 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns gottlobite to the class of "phosphates, arsenates and vanadates" and there to the category of "anhydrous phosphates, etc., with hydroxyl or halogen". Here he is also in the "Adelit group" with the system no. 41.05.01 to be found in the subsection “ Anhydrous phosphates etc., with hydroxyl or halogen with (AB) 2 (XO 4 ) Z q ”.

Crystal structure

Crystal structure of gottlobite
looking in a direction. Blue: vanadate, green: Ca, red: Mg, light blue: O

Gottlobite crystallizes orthorhombically in the space group P 2 1 2 1 2 1 (space group no. 19) with the lattice parameters a  = 7.50  Å ; b  = 9.01 Å and c  = 5.94 Å and 4 formula units per unit cell . Template: room group / 19

Education and Locations

Gottlobit forms in hydrothermal barite - transitions in the conglomerate of the Lower Rotliegenden .

So far (as of 2019) the mineral has only been found at its type locality Gottlob in Thuringia in Germany.

See also

literature

  • Thomas Witzke , Manfred Steins, Thomas Doering, Uwe Kolitsch: Gottlobite, CaMg (VO 4 , AsO 4 ) (OH), a new mineral from Friedrichroda, Thuringia, Germany . In: New yearbook for mineralogy, monthly books . tape 10 , 2000, ISSN  0028-3649 , p. 444-454 .
  • John Leslie Jambor , Andrew C. Roberts: New Mineral Names . In: American Mineralogist . tape 86 , 2000, pp. 767-770 ( rruff.info [PDF; 73 kB ; accessed on October 21, 2019]).
  • Joseph A. Mandarino: New Minerals . In: The Canadian Mineralogist . tape 39 , 2001, p. 1473–1502 ( rruff.info [PDF; 422 kB ; accessed on October 21, 2019] Gottlobit S. 1482).

Web links

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

Individual evidence

  1. ↑ a b Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: September 2019. (PDF 2672 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, September 2019, accessed October 21, 2019 .
  2. ↑ a b c d e 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.  730 (English).
  3. ↑ David Barthelmy: Gottlobite Mineral Data. In: webmineral.com. Retrieved October 21, 2019 .
  4. ↑ a b c d e f g h Thomas Witzke : Discovery of Gottlobit. In: strahlen.org/tw. April 27, 2018, accessed October 21, 2019 .
  5. ↑ a b c d e Gottlobite. In: mindat.org. Hudson Institute of Mineralogy, accessed October 21, 2019 .
  6. ↑ Detailed information on testing and approval of the mineral and all initial descriptors stored in the OTRS
  7. ↑ Gottlobit in the type mineral catalog of the Mineralogical Museum of the University of Hamburg. In: typmineral.uni-hamburg.de. December 7, 2017, accessed October 21, 2019 .
  8. ↑ Catalog of Type Mineral Specimens - G. (PDF 77 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed August 29, 2019 .
  9. ↑ 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 .
  10. ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed October 21, 2019 .
  11. ↑ Find location list for gottlobite in the Mineralienatlas and Mindat , accessed on October 21, 2019.