Violarit

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Violarit
General and classification
chemical formula Fe 2+ Ni 2 3+ S 4
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.DA.05 ( 8th edition : II / D.01)
02.10.01.08
Crystallographic Data
Crystal system cubic
Crystal class ; symbol cubic hexakisoctahedral; 4 / m 3 2 / m
Room group (no.) Fd 3 m (No. 227)
Lattice parameters a  = 9.45  Å
Formula units Z  = 8
Physical Properties
Mohs hardness 4.5 to 5.5
Density (g / cm 3 ) calculated: 4.79
Cleavage completely after {001}
Break ; Tenacity brittle
colour gray-violet
Line color black
transparency opaque
shine Metallic luster

Violarite is a mineral from the mineral class of " sulphides and sulphosalts ", which can sometimes be abundant in various locations, but is generally not very widespread. It crystallizes in the cubic crystal system with the composition Fe 2+ Ni 2 3+ S 4 , so it is chemically an iron - nickel- sulfide.

Violarit is opaque in every form and only forms kidney to massive, metallic, shiny aggregate forms . In normal daylight it usually shows a gray-violet color, which increases to a clearly visible violet in incident light . However, the mineral leaves a black line on the marking board .

Etymology and history

Violarit was first discovered in the "Vermilion Mine" near Denison in the Canadian province of Ontario . described in 1924 Waldemar Lindgren and W. Myron Davy, who named the mineral based on its color after the Latin word "violaceus" for violet.

classification

Already in the now outdated, but still in use 8th edition of the mineral classification according to Strunz , the violarite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "metal: sulfur, selenium, tellurium <1: 1", where it belongs together Bornhardtit , Cadmoindit , Carrollit , daubréelite , Fletcherit , Florensovit , greigite , Indit , Kalininit , linnaeite , Polydymit , Siegenit , Trüstedtit and Tyrrellit the "LineIt group" with the system number. II / D.01 formed.

The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also assigns violarite to the class of “sulfides and sulfosalts”, but in the category of “metal sulfides with M: S = 3 : 4 and 2: 3 “. This department is further subdivided according to the exact molar ratio of metal (M) and sulfur (S), so that the mineral can be found according to its composition in the subdivision "M: S = 3: 4", where it, together with Bornhardtite, Cadmoindit, Carrollit, Cuproiridsit , Cuprorhodsit , daubréelite, Ferrorhodsit , Fletcherit, Florensovit, greigite, Indit, Kalininit, linnaeite, Malanit , Polydymit, Siegenit, Trüstedtit, Tyrrellit and Xingzhongit the "LineIt group" with the system number. 2.DA.05 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the violarit to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here it is together with linneit, carrollite, fletcherite, tyrrellite, bornhardtite, siegenite, polydymite, trüstedtite, greigite, daubréelite, indite, kalininite, florensovite, cuproiridsite, cuprorhodsite, malanite, ferrorhodsite and cadmoindite in the "Linneity group": with the system no. 02.10.01 within the subsection " Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 3: 4 ".

Education and Locations

Violarite is formed from pentlandite through hydrothermal processes and is mostly found as an accessory component in intramagmatic iron-nickel ores.

So far (as of 2012) Violarite has been found at around 235 sites worldwide. Besides its type locality "Vermilion Mine" in Denison yet joined the mineral in many other mines in the provinces of Ontario , Manitoba and Quebec , as well as St. Stephen in the province of New Brunswick , in the "Tilt Cove Mine" at Betts Cove on Newfoundland , in the Rottenstone Mine in Saskatchewan Province and the Wellgreen Cu-Ni-PGE deposit at Kluane near Whitehorse in Yukon.

In Germany, Violarit has so far only been able to use the “Friedrich-August” mine near Horbach near St. Blasien in Baden-Württemberg, the “Lammerichskaule” mine near Oberlahr and the Moschellandsberg ( Landsberg ) near Obermoschel in Rhineland-Palatinate, in the sulphide deposit near Sohland on the Spree in Upper Lusatia in Saxony and in the Ronneburg uranium deposit in Thuringia.

In Austria, the mineral has so far only been found at a few locations, such as in the serpentinite quarry near Griesserhof (Gulitzen) near Hirt in the Friesach - Hüttenberg district (Carinthia), at Totenkopf in the Hohe Tauern (Salzburg), in the "Grube Breitenau " at Hochlantsch (Styria) and at Gumpachkreuz in Hinterbichler Dorfertal in East Tyrol.

In Switzerland, Violarit has so far performed near Oberhalbstein in the canton of Graubünden, in several pits in the municipality of Ayer (Val d'Anniviers) and on the Schwarzhorn in the Binn valley in the canton of Valais.

Other locations include Afghanistan, Egypt, Argentina, Ethiopia, Australia, Belgium, Botswana, Brazil, Bulgaria, China, Finland, France, Greenland, India, Italy, Japan, Kazakhstan, North and South Korea, Mexico, New Zealand, Norway , Pakistan, the Philippines, Russia, Zambia, Sweden, Zimbabwe, Slovakia, Spain, South Africa, the Czech Republic, the United Kingdom (Great Britain), the United States of America (USA), Vietnam.

Crystal structure

Violarit crystallizes cubically in the space group Fd 3 m (space group no. 227) with the lattice parameter a  = 9.45  Å and 8 formula units per unit cell .

See also

literature

  • Waldemar Lindgren, W. Myron Davy: Nickel ores from Key West Mine, Nevada , in: Economic Geology , Volume 19, June – July 1924, pp. 309–319 ( PDF 391.9 kB , p. 12)

Web links

Individual evidence

  1. ↑ Webmineral - Violarite
  2. ↑ a b c d Hugo Strunz , Ernest H. Nickel: Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p.  93 .
  3. ↑ a b c d John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols: Violarite , in: Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 59.8 kB )
  4. ^ Helmut Schrätze, Karl-Ludwig Weiner: Mineralogie. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp. 231 .
  5. ↑ Mindat - Violarite
  6. ↑ Mindat Localities for Violarite