Cuprostibit

from Wikipedia, the free encyclopedia
Cuprostibit
Cuprostibite.jpg
Violet cuprostibite aggregate from the type locality Nakkaalaaq (Ilímaussaq complex ( Narsaq district ), Greenland)
General and classification
chemical formula
  • Cu 2 (Sb, Tl)
  • Cu 2 Sb
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.AA.20
04/02/11/01
Crystallographic Data
Crystal system tetragonal
Crystal class ; symbol ditetragonal-dipyramidal; 4 / m  2 / m  2 / m
Space group P 4 / nmm (No. 129)Template: room group / 129
Lattice parameters a  = 3.99  Å ; c  = 6.09 Å
Formula units Z  = 2
Physical Properties
Mohs hardness 4 (VHN 50 = 216–249)
Density (g / cm 3 ) calculated: 8.42
Cleavage indistinct
Break ; Tenacity uneven
colour Steel gray, red-violet tinge on fresh fracture surfaces, pink-violet in incident light
Line color not defined
transparency opaque (opaque)
shine Metallic luster

Cuprostibite is a rarely occurring mineral from the mineral class of " sulfides and sulfosalts " with the chemical composition Cu 2 (Sb, Tl) (idealized also Cu 2 Sb). From a chemical point of view, cuprostibite is thus a copper - antimonide , in which part of the copper is usually replaced ( substituted ) by thallium .

Cuprostibite crystallizes in the tetragonal crystal system and is mainly found in the form of fine-grain mineral aggregates of up to 1.5 mm in diameter. However, tabular crystal formations from a few tenths to about one millimeter in diameter are also known. The mineral is in any form opaque ( opaque ) and displays on the surfaces of the steel-gray in reflected light and pink violet crystals and aggregates have a metallic luster . On fresh fracture surfaces, the otherwise gray mineral samples can have a tinge of red-violet. The line color has not yet been determined due to the sample size being too small.

Etymology and history

The mineral was first found in mineral samples from 1334 m high Nakkaalaaq (also Nakalak, Nakalaq ) in the alkali complex Ilímaussaq (also Ilimmaasaq ) near Narsaq in the municipality of Kujalleq on the southern tip of Greenland . The first description was in 1969 by Henning Sørensen , EI Semenov, MS Bezsmertnaya and EB Khalezova ( Russian Х. Соренсен, Е. И. Семенов, М. С. Безсмертная, Е. Б. Халезова ) initially in the Russian journal Zapiski Vserossijskogo Mineralogicheskogo Obshchestva . A short description followed a year later by Michael Fleischer and Ernest Henry Nickel in the English-language specialist magazine American Mineralogist .

Sørensen and his team named the mineral after its composition of copper ( Latin cuprum ) and antimony (Latin stibium ).

The type material of the mineral is said to be deposited at the University of Copenhagen in Denmark, but there is no corresponding documentation in the type mineral catalog of the International Mineralogical Association (IMA).

classification

In the outdated 8th edition of the mineral classification according to Strunz , the cuprostibite is not yet recorded. Only in the Lapis mineral directory according to Stefan Weiß, which, out of consideration for private collectors and institutional collections, is still based on this old form of Karl Hugo Strunz's system , was the mineral given the system and mineral number. II / A.01-70 . In the "lapis system" this corresponds to the class of "sulfides and sulfosalts" and there the department "alloys and alloy-like compounds", where cuprostibite together with algodonite , domeykite , domeykit-β , koutekit , kutinaite and novákite are independent but unnamed Group forms (as of 2018).

The 9th edition of Strunz's mineral systematics , which has been valid since 2001 and was updated by the IMA until 2009, also assigns the cuprostibite to the division of "alloys and alloy-like compounds". This is, however, further subdivided according to the predominant metals in the compound, so that the mineral can be found according to its composition in the sub-section "Compounds of semi-metals with copper (Cu), silver (Ag), gold (Au)", where it can be found as is the only member of the unnamed group 2.AA.20 .

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the cuprostibite to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here he is the only member of the unnamed group 04/02/11 within the subsection “Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 2: 1”.

Crystal structure

Cuprostibite crystallizes tetragonally in the space group P 4 / nmm (space group no. 129) with the lattice parameters a = 3.99  Å and c = 6.09 Å as well as two formula units per unit cell . Template: room group / 129

Education and Locations

Cuprostibit aggregate from the type locality Nakkaalaaq, Sweden (field of view 1.8 cm)

At its type locality Nakkaalaaq in the Ilímaussaq complex on Greenland , cuprostibite formed in ussingite - veins that traversed the upcoming sodalite - syenite . Chalcopyrite , chalcothallite , lollingite and antimony-containing silver were found here as accompanying minerals . Depending on where it was found, other parageneses such as solid antimony and bismuth , broad-headed , chalcosine , dyscrasite ( antimony silver ), galena , gudmundite and sphalerite can occur.

As a rare mineral formation, cuprostibite could only be detected in a few places, with fewer than 20 sites being documented worldwide (as of 2020). In addition to the Nakkaalaaq, the mineral also occurred on the nearby Kuannersuit Plateau (also Kvanefjeld ) and on the Taseq .

Within Europe, cuprostibit has so far been found at Herrsättra near Långsjön in the province of Södermanlands län and at Långban in the province of Värmlands län in Sweden, on the slag heaps of the Castleside lead smelter near Healeyfield in the English county of Durham , on the slag dumps La Fonderie in the municipality of Poullaouen (Brittany) and Fonderie de Vialas in the municipality of Vialas (Occitania) in France and in "Uranium shaft 16" near Háje u Příbramě in the Czech Republic

Other previously known sites are in the Aqmola (also Akmola ) area of ​​Kazakhstan, in the Soimon Valley near Karabash (Chelyabinsk Oblast, Urals) as well as in the Sakha Republic ( Yakutia ) and on Kamchatka in Russia and in Franklin in the US state of New Jersey .

See also

literature

  • Х. Соренсен, Е. И. Семенов, М. С. Безсмертная, Е. Б. Халезова: Купростибит - Новое приро дное Соединение меди и Сурьмы . In: Zapiski Vserossijskogo Mineralogicheskogo Obshchestva . tape 98 , 1969, p. 716–724 (Russian, rruff.info [PDF; 817 kB ; accessed on June 28, 2020] English translation: H. Sørensen, EI Semenov, MS Bezsmertnaya, EB Khalezova: Cuprostibite, a new natural compound of copper and antimony ).
  • Michael Fleischer , Ernest H. Nickel : New mineral names . In: American Mineralogist . tape 55 , 1970, pp. 1810–1818 (English, rruff.info [PDF; 600 kB ; accessed on June 28, 2020]).
  • WB Pearson: The Cu 2 Sb and related structures . In: Journal of Crystallography . tape 171 , 1985, pp. 23–39 (English, rruff.info [PDF; 655 kB ; accessed on June 28, 2020]).

Web links

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

Individual evidence

  1. ↑ a b c d 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 .
  2. ↑ a b Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: March 2020. (PDF; 2.44 MB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, March 2020, accessed June 28, 2020 .
  3. ↑ 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.  58 (English).
  4. ↑ a b c d e f g Cuprostibite . 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; 64  kB ; accessed on June 27, 2020]).
  5. ↑ Image of one-tenth of a millimeter cupro dibite crystals from the slag locality Castleside, Healeyfield, County Durham, England. In: mindat.org. Hudson Institute of Mineralogy, accessed June 28, 2020 .
  6. ↑ Image of a millimeter-sized cuprostibite crystal from the slag locality Vialas, Lozère, Occitania, France. In: mindat.org. Hudson Institute of Mineralogy, accessed June 28, 2020 .
  7. ↑ Catalog of Type Mineral Specimens - C. (PDF 131 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed June 28, 2020 .
  8. ↑ Ernest H. Nickel , Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF; 1.82 MB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed June 28, 2020 .
  9. ↑ Localities for Cuprostibite. In: mindat.org. Hudson Institute of Mineralogy, accessed June 28, 2020 .
  10. ↑ List of locations for cuprostibite from the Mineralienatlas and Mindat , accessed on June 28, 2020.