Yarrowit

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Yarrowit
General and classification
other names

IMA 1978-022

chemical formula Cu 9 S 8
Mineral class
(and possibly department)
Sulphides and sulphosalts - metal sulphides, M: S> 1: 1
System no. to Strunz
and to Dana
2.CA.05d ( 8th edition : II / B.01)
07/02/03/01
Crystallographic Data
Crystal system hexagonal
Crystal class ; symbol 3 m , 32 or 3 m
Space group P 3 m 1, P 3 m 1, P 31 m or P 321
Lattice parameters a  = 3.80  Å ; c  = 67.26 Å
Formula units Z  = 3
Physical Properties
Mohs hardness Please complete!
Density (g / cm 3 ) 4.89
Cleavage Please complete!
colour blue
Line color Please complete!
transparency opaque
shine metallic
Crystal optics
Pleochroism blue to blue-white

Yarrowit is a rare mineral from the mineral class of sulfides and sulfosalts . It crystallizes in the hexagonal crystal system with the chemical formula Cu 9 S 8 and forms massive or star-shaped mineral aggregates of blue color.

Etymology and history

Yarrowit was founded in 1980 by RJ Goble at Yarrow Creek in the southwest of the Canadian province of Alberta found. He named it after the place where it was found. The type locality of the very similar spy copite is located in the vicinity of the site . Before the discovery in Canada, blue covellin was known, which was first synthesized in 1959 by G. Frenzel. It was not a uniform material, but both Yarrowit and Spionkopit.

classification

Yarrowit is in the system after Strunz counted as sulfides and sulfosalts. In the 8th edition, it belongs to the subgroup of copper sulphides of sulphides and sulphosalts with a ratio of metal to sulfur of greater than 1: 1, together with anilite , chalcosine , digigenite , djurleit , geerite , roxbyite and spionkopite .

In the 9th edition of the systematics , Covellin, Klockmannit and Spionkopit are part of the Covelling group, a subgroup of sulfides and sulfosalts with a ratio of metal to sulfur of 1: 1 and copper .

According to the Dana system , Yarrowit forms its own subgroup of sulfides, selenides and tellurides with the composition A m B n X p and the ratio of (m + n) to p of 9: 8.

Modifications and varieties

Yarrowit counts with Chalcosin, Djurleit, Anilith and Spionkopit to a mixed crystal series with different stoichiometric ratios of copper and sulfur which forms at low temperatures (<100 ° C) .

Education and Locations

Since Yarrowit is metastable , it only forms under special conditions at low temperatures, when the formation of the stable phases anilite and chalcosine are kinetically inhibited, through weathering of other copper sulphides. It is with Anilith, djurleite, Spionkopit and Tennantit socialized .

In addition to the type locality and other places in Canada, Yarrowit has been in Graz and Köflach in Austria , the Black Forest , Spessart , Hunsrück , Harz as well as the Mansfeld Basin and Horscha in Germany , Saint-Luc in the Swiss canton of Valais , Kolwezi in the Democratic Republic Congo , Bogor on the Indonesian island of Java , Ardakan in Iran , Killarney in Ireland , Sondrio in Italy , Iwaki and Shimohei in Japan , Lubin in Poland , Gümüşhane in Turkey, Caldbeck Fells , Stanton under Bardon , Cannington , Nuneaton and Wethel in the United States Kingdom and the US states of Arizona , New Mexico and Virginia .

Crystal structure

Yarrowit crystallizes in the hexagonal crystal system with the space group P 3m1, P 3 m1, P 31m or P 321, the lattice parameters a = 3.80  Å and c = 67.26 Å, and three formula units per unit cell .

See also

Individual evidence

  1. a b c d R.J. Goble: Copper sulfides from Alberta: yarrowite, Cu 8 S 9 , and spionkopite, Cu 39 S 28 . In: Canadian Mineralogist. 1980, 18, pp. 511-518 ( abstract in American Mineralogist, p. 1279 ; PDF; 873 kB).
  2. ^ A. Putnis, J. Grace, WE Cameron: Blaubender covellite and its relationship to normal covellite. In: Contributions to Mineralogy and Petrology. 60, 1977, pp. 209-217, doi : 10.1007 / BF00372282 .
  3. ^ New Dana Classification of Sulfide Minerals
  4. a b Hubert Lloyd Barnes: Geochemistry of hydrothermal ore deposits, Volume 1. 3rd Edition, John Wiley and Sons, 1997 ISBN 0-471-57144-X , pp. 390–392 ( limited preview in the Google book search).
  5. Yarrowit at mindat.org

literature

  • Yarrowit. In: Anthony et al .: Handbook of Mineralogy , 1990, 1, 101 ( pdf )

Web links