Atelestite

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Atelestite
Atelestite-824233.jpg
Light yellow atelestite crystals on a matrix from the type locality Grube Neuhilfe near Neustädtel, Erzgebirge, Saxony ( overall size : 3.1 cm × 2.7 cm × 1.1 cm)
General and classification
other names

Rhagit

chemical formula
  • Bi 2 [O | OH | AsO 4 ]
  • Bi 2 O (AsO 4 ) (OH)
Mineral class
(and possibly department) 		Phosphates, arsenates and vanadates
System no. to Strunz
and to Dana 		8.BO.15 ( 8th edition : VII / B.18)
11.11.05.01
Crystallographic Data
Crystal system monoclinic
Crystal class ; symbol monoclinic prismatic; 2 / m
Space group P 2 1 / c (No. 14)Template: room group / 14
Lattice parameters a  = 7,000  Å ; b  = 7.430 Å; c  = 10.831 Å
β  = 107.08 °
Formula units Z  = 4
Frequent crystal faces {10 1 }, {010}, {100},} 20 1 }, {111}, {110},} 21 1 }
Physical Properties
Mohs hardness 4.5 to 5
Density (g / cm 3 ) measured: 7.14; calculated: 6.95
Cleavage indistinct after {100}
Break ; Tenacity slightly mussel-like
colour light yellow to sulfur yellow, yellowish green, black; light yellow to colorless in transmitted light
Line color White
transparency transparent to translucent
shine Resin gloss to diamond gloss
Crystal optics
Refractive indices n α  = 2.140
n β  = 2.150
n γ  = 2.180
Birefringence δ = 0.040
Optical character biaxial positive
Axis angle 2V = 42 ° to 46 ° (measured), 62 ° (calculated)

Atelestit is a rarely occurring minerals from the mineral class of "phosphates, arsenates, and vanadates" with the chemical composition of Bi 2 [O | OH | AsO 4 ] and is therefore chemically seen a bismuth - arsenate with additional oxygen - and hydroxide ions .

Atelestite crystallizes in the monoclinic crystal system , but develops only tiny, tabular to prismatic crystals up to about two millimeters in length with a resin-like to diamond-like sheen on the surfaces. Nipple-shaped to conical-shaped and spherical aggregate shapes are also known .

The transparent to translucent crystals are light yellow to sulfur yellow, yellowish green or black in color. Atelestite appears light yellow to colorless in transmitted light. However, its line color is always white.

Etymology and history

A first brief description of the mineral was published by August Breithaupt in 1832 in his work Complete Characteristics of the Mineral System . However, he limited himself to the characterization of a few properties such as color, gloss, transparency and crystal form. In the sample described by Breithaupt, the delicate atelestite crystals sit on "bismuth blende ore" ( identical to Eulytin according to Witzke ) from Schneeberg in the Ore Mountains . The chemical composition is missing from the short description, as is an explanation of the chosen name atelestite.

However , there has never been a “ new aid pit ” in the Schneeberg-Neustädtel mining area. As with the Paulkellerit , the correct location is the Neuhilfe Flacher passage of the Junge Kalbe mine in Schneeberg-Neustädtel.

In the Handbuch der Mineralogie , which Carl Hintze published in 1933, the name is explained by the fact that it is based on the Greek term άτελής [ateles] for imperfect , because the chemical composition of the mineral was initially unknown. This was first determined in 1889 by Karl Busz on samples from the Neuhilfe mine near Neustädtel (Schneeberg) . The given oxide formula 3 Bi 2 O 3  · As 2 O 5  · 2 H 2 O corresponds to the formula Bi 3 (AsO 4 ) O 2 (OH) 2 in modern notation . After more recent analyzes in 1986, K. Mereiter and A. Preisinger finally simplified the formula to Bi 2 (AsO 4 ) O (OH) (also Bi 2 O (AsO 4 ) (OH)), which corresponds to the crystal chemical structural formula Bi 2 [O | OH | AsO 4 ].

Before it was recognized as an independent type of mineral, Brendelite was initially thought of as atelestite due to its appearance.

classification

Already in the outdated 8th edition of the mineral classification by Strunz of Atelestit belonged to the mineral class of "phosphates, arsenates and vanadates" and then to the Department of "water clear phosphates, arsenates and vanadates with foreign anions " where he along with Georgiadesit and Sahlinit the " Georgiadesit-Sahlinit-Atelestit-Gruppe “with the system no. VII / B.18 .

In the revised and updated Lapis mineral directory by Stefan Weiß, which, out of consideration for private collectors and institutional collections, is still based on the old form of Karl Hugo Strunz's system , the mineral was given the system and mineral no. VII / B.30-02 . In the “Lapis system” this also corresponds to the section “Anhydrous phosphates, with foreign anions F, Cl, O, OH”, where atelestite forms an independent but unnamed group together with hechtsbergite , petitjeanite , priceingerite , Schlegelite , Schumacherite and Smrkovecite (As of 2018).

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 assigns the atelestite to the department 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 molar ratio of the additional anions (OH, etc.) to the phosphate, arsenate or vanadate complex (RO 4 ), so that the mineral according to its composition in the subsection “With exclusively large cations; (OH, etc.): RO 4  ≥ 1: 1 ”can be found where the“ Atelestitgruppe ”with the system no. 8.BO.15 and the other members hechtsbergite and smrkovecite .

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , also assigns atelestite to the class of "phosphates, arsenates and vanadates" and there in the category of "anhydrous phosphates etc., with hydroxyl or halogen". Here he is the only member of the unnamed group 11/41/05 within the sub-section “Anhydrous phosphates etc., with hydroxyl or halogen with different formulas”.

Crystal structure

Atelestite crystallizes monoclinically in the space group P 2 1 / c (space group no. 14) with the lattice parameters a  = 7,000  Å ; b  = 7.430 Å; c  = 10.831 Å and β = 107.08 ° and 4 formula units per unit cell . Template: room group / 14

Modifications and varieties

Under the designation Rhagit (from the Greek ῥαγες Rhages for grape or ῥαγοιδης or ῥαγωδης, rhagodes or rhagoïdes for cluster-like) described in 1874 Albin Weisbach occurring a traubigen spherically-in, the fine crystalline aggregates, bright yellowish green to wine beer green Bismutarsenat that in the White Hirsch repertory at Schneeberg was discovered. It was not until 1943 that Clifford Frondel was able to prove, by comparing the X-ray powder diffraction (see also Debye-Scherrer method ), that atelestite and rhagite have a practically identical composition. The mineral name Rhagite was therefore discredited and has been a synonym for atelestite ever since.

Education and Locations

Atelestit formed secondarily in the oxidation zone of bismuth- or arsenic deposits . As accompanying minerals may include Beyerit , Bismutit , Bismutostibiconit , Erythrite , Eulytin , Konichalcit , Mixit , Preisingerit , quartz , Torbernit and Walpurgin occur.

In addition to its type locality , the Neuhilfe mine, Atelestite could also be discovered in Saxony in several pits in the Schneeberg mining area. In addition, the mineral appeared in the Hohes Genist mine (also Ascension (Christ) ) near Steinbach in the Johanngeorgenstadt mining district and in the Alexander and Pucher pits in the St. Wolfgang and Maaßen mining district . Atelestite was also found in several places in the Black Forest in Baden-Württemberg, such as the Clara mines near Oberwolfach, Dorothea near Freudenstadt and Königswart near Schönegründ (municipality of Baiersbronn ) as well as in the Hessian Odenwald near Gadernheim and at Hohenstein near Reichenbach (Lautertal) .

The only known site in Austria so far is the Tramerscharte in the Zirknitzer Valley in the Goldberg group in Carinthia. In Switzerland , too , the mineral is known from one place of discovery, namely the Mine de Collioux inférieur near Saint-Luc in the canton of Valais .

Other locations are in England (UK), Finland , France , Greece , Spain and the Czech Republic as well as in the US state of Utah .

See also

literature

  • August Breithaupt : Atelestit . In: Complete characteristics of the mineral system . Arnoldische Buchhandlung, Dresden 1832, p. 307 ( rruff.info [PDF; 79 kB ; accessed on December 21, 2019]).
  • KB Culver, LG Berry: Flinkite and atelestite . In: The Canadian Mineralogist . tape 7 , 1963, pp. 547–553 ( rruff.info [PDF; 352 kB ; accessed on December 21, 2019]).
  • Joel D. Grice, Giovanni Ferraris: New minerals approved in 2002 and nomenclature modifications approved in 1998-2002 by the Commission on the New Minerals and Mineral Names, International Mineralogical Association . In: The Canadian Mineralogist . tape 41 , 2003, p. 795–802 ( rruff.info [PDF; 44 kB ; accessed on June 7, 2018]).
  • 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. 653 .
  • Petr Korbel, Milan Novák: Mineral Encyclopedia (=  Villager Nature ). Edition Dörfler im Nebel-Verlag, Eggolsheim 2002, ISBN 978-3-89555-076-8 , p. 174 .

Web links

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

Individual evidence

  1. ^ Friedrich Klockmann : Klockmanns textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp.  639 (first edition: 1891).
  2. ^ A b Albin Weisbach : Mineralogical notes. 1. Pucherite. 2. Domeykit. 3. Rhagit. 4. Roselith . In: Yearbook for mining and metallurgy in the Kingdom of Saxony . 1874, p.  249-254 .
  3. ^ 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.  469 (English).
  4. ↑ Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: November 2019. (PDF 1720 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, November 2019, accessed December 21, 2019 .
  5. ^ David Barthelmy: Atelestite Mineral Data. In: webmineral.com. Retrieved December 21, 2019 .
  6. ↑ a b c Kurt Mereiter, Anton Preisinger: Crystal structure data of the bismuth minerals atelestite, mixite, and pucherite . In: Anzeiger der Österreichische Akademie der Wissenschaften, Mathematisch-Naturwissenschaftliche Klasse, Anzeiger . tape 123 , 1986, pp. 79–81 ( published on researchgate.net [accessed December 21, 2019]).
  7. ↑ a b c d e f g Atelestite . 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 December 21, 2019]).
  8. ↑ a b c d e Atelestite. In: mindat.org. Hudson Institute of Mineralogy, accessed December 21, 2019 .
  9. ↑ a b Thomas Witzke : Discovery of Atelestit. www.strahl.org/tw, June 24, 2017, accessed December 21, 2019 .
  10. ↑ Thomas Witzke : A new bismuth phosphate from Schneeberg. www.strahl.org/tw, June 24, 2017, accessed December 21, 2019 .
  11. ↑ 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 .
  12. ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1816 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed December 21, 2019 .
  13. ↑ Ludwig August Kraus: Critical-etymological medicinisches Lexikon for the words of Greek origin that occur most frequently in the language of doctors . Rudolf Deuerlich, Göttingen 1821, p. 599 ( limited preview in Google Book search).
  14. ^ KC von Leonhard, HG Bronn, G. Leonhard, HB Geinitz (ed.): New year book for mineralogy, geology and palaeontology . E. Schweizerbart'sche Verlagshandlung, Stuttgart 1874, p. 302–303 ( available online at archive.org  - Internet Archive ).
  15. ^ Clifford Frondel : New data on agricolite, bismoclite, koechlinite, and the bismuth arsenates . In: American Mineralogist . tape  28 , no. 9-10 , 1943, pp. 536-540 ( minsocam.org [PDF; 304 kB ; accessed on December 21, 2019]).
  16. ↑ Find location list for atelestite in the Mineralienatlas and Mindat , accessed on December 21, 2019.