Vaesit

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Vaesit
Vaesite-626130.jpg
Octahedral vaesite crystals on matrix from the province of Modena , Emilia-Romagna, Italy (field of view: 3 mm)
General and classification
chemical formula NiS 2
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.EB.05a ( 8th edition : II / C.05)
02.12.01.02
Crystallographic Data
Crystal system cubic
Crystal class ; symbol cubic-disdodecahedral; 2 / m  3
Space group Pa 3 (No. 205)Template: room group / 205
Lattice parameters a  = 5.69  Å
Formula units Z  = 4
Physical Properties
Mohs hardness ≈ 3.5 ( VHN 100 = 743–837 kg / mm²)
Density (g / cm 3 ) measured: 4.45; calculated: 4.47
Cleavage completely after {001}
colour steel gray, black
Line color black
transparency opaque (opaque)
shine Metal gloss to semi-metal gloss

Vaesite is a seldom occurring mineral from the mineral class of "sulphides and sulphosalts" with the chemical composition NiS 2 and thus, chemically speaking, nickel disulphide .

Vaesit crystallizes in the cubic crystal system and develops octahedral or cube-shaped crystals up to one centimeter in size with a metallic sheen on the surfaces. But it also occurs in the form of coarse mineral aggregates . The mineral, which is opaque in every form, is generally steel-gray to black in color and shows a light gray-violet reflection color under the incident light microscope .

Etymology and history

As early as 1840, Ludwig Rudolf von Fellenberg is said to have synthesized nickel disulfide from a melt of NiCO 3 and K 2 CO 3 .

Was used as a naturally formed mineral connection but only 100 years later, in September 1943 in the Kasompi Mine (also Menda Mine ), a nickel- copper - cobalt - deposit at the same hills some 70 kilometers west-southwest of Kambove in the former Belgian colony Discovered the Belgian Congo (now the Democratic Republic of the Congo ). Its discoverer, the Belgian mineralogist Johannes Franciscus Vaes (1902–1978), was working at the time for the mining company Union Minière du Haut Katanga and found the mineral in a drill core that was extracted while driving the diamond drillings in the Kasompi mine. Another mineral, later known as cattierite , was discovered in the nearby Shinkolobwe mine .

Vaes carried out independent mineralogical studies on the two newly discovered sulphide minerals and was able to determine the chemical composition NiS 2 for the mineral from the Kasompi mine and CoS 2 for the mineral from the Shinkolobwe mine. The preliminary results of the investigation led Vaes to suspect that the minerals could belong to the pyrite group.

The two minerals were examined in the laboratories of Columbia University by Paul Francis Kerr . He was able to confirm their composition and identify them as new types of mineral. In his first description published in 1945, he named nickel disulphide in honor of its discoverer Vaesit.

The type material of the mineral may have been kept at Columbia University and is now believed to be deposited in the American Museum of Natural History in New York (USA). However, the storage location is not confirmed by the IMA type mineral catalog.

classification

Already in the outdated 8th edition of the mineral classification according to Strunz , the vaesite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "sulfides with M: S <1: 1", where it belongs together with Aurostibit , Cattierit , Geversit , Hauerit , Laurite , michenerite , penroseit , pyrite , sperrylite , trogtalite and villamanínite the "pyrite series" with the system no. II / C.05 formed.

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 , the mineral was given the system and mineral number. II / D.17-50 . In the "Lapis system" this also corresponds to the section "Sulphides with metal: S, Se, Te <1: 1", where vaesite together with aurostibite, cattierite, changchengit , dzharkenite , erlichmanite , fukuchilit , Geversit, Hauerit, Insizwait , Krutaite , Laurit, Maslovit , Mayingit , Michenerit, Padmait , Penroseite, pyrite, Sperrylith, Trogtalit, Testibiopalladit and Villamanínit the "pyrite 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, classifies the vaesite in the more general section of “metal sulfides with M: S ≤ 1: 2”. However, this is further subdivided according to the exact molar ratio and the predominant metals in the compound, so that the mineral can be found in the sub-section "M: S = 1: 2, with Fe, Co, Ni, PGE etc." according to its composition where it together with Aurostibit, cattierite, Dzharkenit, Erlichmanit, Fukuchilit, Gaotaiit , Geversit, Hauerit, Insizwait, Iridisit , Krutaite, Laurit, Penroseite, pyrite, Sperrylith, Trogtalit and Villamanínit the "pyrite group" with the system no. 2.EB.05a forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Vaesit to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here it is also in the "pyrite group (isometric: Pa 3 )" with the system no. 02.12.01 to be found within the subsection “ Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 1: 2 ”. Template: room group / 205

Chemism

According to the idealized (theoretical) composition of vaesite (NiS 2 ), the mineral consists of 47.78% nickel (Ni) and 52.22% sulfur (S).

In natural vaesites, however, a small part of the nickel can always be replaced ( substituted ) by cobalt due to the formation of mixed crystals with the cobalt disulfide cattierite . In addition, the microprobe analysis on the type material from the Kasompi mine and samples from Kalgoorlie in Australia revealed small amounts of iron (Fe) between 2.2 and 2.6%.

Crystal structure

Vaesite crystallizes cubically in the pyrite structure in the space group Pa 3 (space group no. 205) with the lattice parameter a  = 5.69  Å and 4 formula units per unit cell . Template: room group / 205

Modifications and varieties

In the hitherto only known variety of vaesite, which is also known as selenio vaesite or selenvaesite , selenium replaces part of the sulfur. Selenvaesite therefore corresponds to the mixed formula Ni (S, Se) 2 .

Education and Locations

Vaesite is formed by weathering or as a conversion product of arsenic-undersaturated nickel cutterudite ( chloanthite ). At his type locality , the Kasompi Mine in the Democratic Republic of the Congo, he found himself embedded in dolomite . In addition to nickel cutter audite , polydymite , pyrite and uraninite appeared as accompanying minerals .

As a rare mineral formation, Vaesit is only known from a few localities, with slightly more than 100 localities being documented. Apart from its type locality Kasompi Mine and the Shinkolobwe Mine, both of which are located in the province of Haut-Katanga , no other site is known to have been found in the Democratic Republic of the Congo.

In Germany, the mineral has so far occurred in the Clara mines near Oberwolfach and Marie in the Kohlbach near Hohensachsen in Baden-Württemberg, in the former lead, silver and fluorite mine Fürstenzeche near Lam in Bavaria, in the Wolfsberg mine near Iba as well the Schnepfenbusch mine near Bauhaus , the nearby Münden mine and the former cobalt and barite mine, Wechselschacht near Suss (Nentershausen) in the Richelsdorf Mountains of Hesse, the calcite quarry near Holzen , the Schöne Aussicht pits near Burbach and Stahlberg near Müsen, the Breinigerberg ore mines , Diepenlinchen and satisfaction, and in the Mechernicher Bleiberg mining area in North Rhine-Westphalia, the Fischbacher mine near Niederfischbach in Rhineland-Palatinate, in a Devonian antimony mineralization near Dietersdorf (southern Harz) in Saxony-Anhalt, on the dump of the father Abraham mine ( shaft 139 ) near Lauta (Marienberg) and in the Schlema - Alberoda - Hartenstein mining district , near Schneeberg im Saxon Erzgebirgskreis and in the former uranium mine Schmirchau in the town of the same name in Thuringia.

In Austria Vaesit found so far on the northern edge of the Brennkogel of the mining area and in Erasmus tunnel Leogang -Schwarzleo in the Salzburg district Zell am See , in rock samples from the Gallows Hill Tunnel in Sankt Michael in Obersteiermark and in Gertraud tunnels on major Kogel near St. Gertraudi in Tyrol.

Other locations include Argentina, Azerbaijan, Australia, Bolivia, Brazil, Bulgaria, China, Finland, France, Greece, India, Italy, Japan, Canada, Morocco, North Macedonia, Norway, Poland, Romania, Russia, Zambia, Saudi Arabia, Zimbabwe, Slovakia, Spain, Czech Republic, Hungary, the United Kingdom (England, Scotland) and the United States of America (Arizona, Illinois, California, Maine, Missouri).

See also

literature

  • Paul F. Kerr: Cattierite and vaesite: New Co-Ni minerals from the Belgian Congo . In: American Mineralogist . tape 30 , 1945, p. 483–497 (English, rruff.info [PDF; 973 kB ; accessed on March 3, 2020]).
  • E. Nowack, D. Schwarzenbach, W. Gonschorek, T. Hahn: Deformation densities in CoS 2 and NiS 2 with pyrite structure . In: Journal of Crystallography . tape 186 , 1989, pp. 213–216 (English, rruff.info [PDF; 131 kB ; accessed on March 3, 2020]).

Web links

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

Individual evidence

  1. ↑ a b c d 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.  103 (English).
  2. ↑ Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: January 2020. (PDF 1729 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, January 2020, accessed March 3, 2020 .
  3. ↑ a b c d e f g h Vaesite . 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 March 3, 2020]).
  4. ↑ 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 .
  5. ↑ Vaesite. In: mindat.org. Hudson Institute of Mineralogy, accessed March 3, 2020 .
  6. ^ Paul F. Kerr: Cattierite and vaesite: New Co-Ni minerals from the Belgian Congo . In: American Mineralogist . tape 30 , 1945, p. 483–497 (English, rruff.info [PDF; 973 kB ; accessed on March 3, 2020]).
  7. ↑ Catalog of Type Mineral Specimens - V. (PDF 40 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed March 3, 2020 .
  8. ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1816 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed March 3, 2020 .
  9. ↑ David Barthelmy: Vaesite MineralData. In: webmineral.com. Retrieved March 3, 2020 .
  10. ↑ Seleniovaesite. In: mindat.org. Hudson Institute of Mineralogy, accessed March 3, 2020 .
  11. ↑ Localities for Vaesite. In: mindat.org. Hudson Institute of Mineralogy, accessed March 3, 2020 .
  12. ↑ a b List of locations for Vaesit in the Mineralienatlas and Mindat , accessed on March 3, 2020.