Kassit

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Kassit
Kassite, Cafetite, Lizardite-529446.jpg
Light yellow cassite spherulites with yellow-orange , tabular cafetite crystals in a matrix of lizardite (image width 2 mm)
General and classification
chemical formula
  • CaTi 2 (OH) 2 O 4
  • CaTi 2 O 4 (OH) 2
Mineral class
(and possibly department) 		Oxides and hydroxides
System no. to Strunz
and to Dana 		4.DH.10 ( 8th edition : IV / D.20)
03/08/09/01
Crystallographic Data
Crystal system orthorhombic
Crystal class ; symbol not defined
Space group not defined
Lattice parameters a  = 5.23  Å ; b  = 9.08 Å; c  = 4.78 Å
Formula units Z  = 2
Twinning spread according to {101} and {181}
Physical Properties
Mohs hardness 5
Density (g / cm 3 ) measured: 3.42; calculated: 3.418
Cleavage completely after {010}, clearly after {101}
Break ; Tenacity very brittle
colour colorless, light yellow, brown-red
Line color White
transparency translucent
shine Diamond luster
magnetism paramagnetic
Crystal optics
Refractive indices n α  = 1.950
n β  = 2.130
n γ  = 2.210
Birefringence δ = 0.260
Optical character biaxial negative
Axis angle 2V = 58 ° (measured); 62 ° (calculated)
Other properties
Chemical behavior insoluble in acids

Kassite is a very rarely occurring mineral from the mineral class of "oxides and hydroxides" with the chemical composition CaTi 2 (OH) 2 O 4 and is therefore chemically a basic calcium - titanium - oxide .

Kassite crystallizes in the orthorhombic crystal system and develops flattened, leafy and pseudo-hexagonal crystals up to a millimeter in size and a diamond-like sheen on the surfaces. The translucent crystals are brown-red or light yellow in color and are often arranged in rosette-shaped mineral aggregates . Colorless cassites are also known.

Etymology and history

Kassit was first discovered in the Afrikanda massif (Russian: Африканда) in the Murmansk Oblast on the Russian Kola Peninsula . The mineral was first described in 1965 by Alexander Alexandrowitsch Kucharenko , MP Orlova, AG Bulakh, EA Bagdasarov, OM Rimskaya-Korsakova, YI Nefedov, GA Ilyinskiy, AC Sergeyev and NB Abakumova. They named the mineral after the geologist Nikolai Grigor'evich Kassin (1885–1949), who discovered the Afrikanda massif.

Type material of the mineral is in the Mineralogical Museum of the University of Saint Petersburg under the catalog no. Retained in 17402.

classification

Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the cassite belonged to the mineral class of "oxides and hydroxides" and there to the department of "oxides with a molar ratio of metal: oxygen = 1: 2 (MO 2 and related compounds) “, Where together with Cafetit , Kobeit- (Y) and Lucasit- (Ce) it formed the unnamed group IV / D.20 .

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 classifies the cassite in the oxides division with a substance ratio of “metal: oxygen = 1: 2 and comparable”. However, this is further subdivided according to the relative size of the cations involved and the crystal structure, so that the mineral is classified in the sub-section “With large (± medium-sized) cations; Layers of edge-linked octahedra "can be found where only together with Lucasite- (Ce) the" Lucasite group "with the system no. 4.DH.10 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the cassite to the class of "oxides and hydroxides", but there in the category of "multiple oxides with Nb, Ta and Ti". Here he is to be found as the only member of the unnamed group 08.03.09 within the sub-section “Multiple oxides with Nb, Ta and Ti and the formula A (B 2 O 6 )”.

Crystal structure

The crystal structure of Kassite was in the first description of 1965 as orthorhombic with the lattice parameters a  = 8.99 + 0.03  Å ; b  = 9.55 + 0.03 Å and c  = 5.26 + 0.01 Å determined, but without specifying the space group and the number of formula units per unit cell .

Peter G. Self and Peter R. Buseck re-analyzed the structure of Kassite in 1991 using samples from Josephine Creek in the county of the same name in the US state of Oregon and also came to the conclusion that Kassite crystallizes in orthorhombic symmetry, but with the corrected lattice parameters a  = 9.08 Å; b  = 4.78 Å and c  = 5.23 Å.

In the analysis of a detection of Kassitkristallen in a proportion of 2% by weight Cr 2 O 3 from the chromite - deposit Saranowskoje near Gornozavodsk in the Russian Perm analyzed and 2003 published by IE Gray, WG Mumme, IV and D. Yu Pekov . Pushcharovsky, for monoclinic symmetry and the space group P 2 1 / a (space group no. 14, position 3) the lattice parameters a  = 5.275 (1) Å, b  = 9.009 (2) Å, c  = 9.557 (2) Å and β = 90.43 ° determined. Template: room group / 14.3

Education and Locations

Kassite forms in alkaline pegmatites and was discovered at its type locality in the Afrikanda massif on Kola as a lining of miarolithic cavities. Cafetite , perovskite and titanite appeared as accompanying minerals . In addition, the mineral could be discovered in Russia in the nearby Chibinen , more precisely on the Razvumchorr and on the Yukspor as well as in the chromite deposit Saranovskoye near Gornozavodsk in the Urals federal district .

Kassite was found associated with ilmenite , perovskite, rutile and titanite in the Josephine Creek polymetallic ore deposit in Josephine County , Oregon .

Other previously known sites are the sedimentary iron ore deposit of volcanic origin near Wugang in the Chinese province of Henan , the Val di Serra marble quarry near Pilcante in the Vallagarina in the Italian province of Trento, a tin ore deposit near Hat Yai in the Thai province of Songkhla, an unnamed gypsum - and anhydrite mine near Perkupa in Borsod-Abaúj-Zemplén County, Hungary, and the Diamond Jo quarry at the Magnet Cove Complex in Hot Spring County , Arkansas

See also

literature

  • AA Kukharenko, MP Orlova, AG Bulakh, EA Bagdasarov, OM Rimskaya-Korsakova, YI Nefedov, GA Ilyinskiy, AC Sergeyev, NB Abakumova: The Caledonian ultrabasic alkalic rocks and carbonatites of the Kola Peninsula and northern Karelia . In: Izdaltelstvo “Nedra” . Moscow 1965, p. 372-375 .
  • Michael Fleischer : New Mineral Names . In: the American Mineralogist . tape 52 , no. 3-4 , 1967, pp. 559–564 (English, minsocam.org [PDF; 455 kB ; accessed on September 16, 2019]).
  • Howard T. Evans Jr., Edward J. Dwornik, Charles Milton: Kassite from the Diamond Jo quarry, Magnet Cove, Hot Spring County, Arkansas: The problem of cafetite and kassite . In: American Mineralogist . tape 71 , 1986, pp. 1045–1048 (English, minsocam.org [PDF; 418 kB ; accessed on September 16, 2019]).
  • Peter G. Self, Peter R. Buseck: Structure model for kassite, CaTi 2 O 4 (OH) 2 . In: American Mineralogist . tape 76 , 1991, pp. 283–287 (English, minsocam.org [PDF; 564 kB ; accessed on September 16, 2019]).
  • IE Gray, WG Mumme, IV Pekov, D. Yu. Pushcharovsky: The crystal structure of chromian kassite from the Saranovskoye deposit, Northern Urals, Russia . In: American Mineralogist . tape 88 , 2003, p. 1331–1335 (English, rruff.info [PDF; 429 kB ; accessed on September 16, 2019]).

Web links

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

Individual evidence

  1. ^ A b c 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.  222 .
  2. ↑ Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: September 2019. (PDF 2672 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, September 2019, accessed September 16, 2019 .
  3. ↑ a b c d Kassite . 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; 73  kB ; accessed on September 16, 2019]).
  4. ↑ a b c 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. ↑ a b c d Michael Fleischer : New Mineral Names . In: the American Mineralogist . tape  52 , no. 3-4 , 1967, pp. 559–564 (English, minsocam.org [PDF; 455 kB ; accessed on September 16, 2019]).
  6. ↑ a b c d e Kassite. In: mindat.org. Hudson Institute of Mineralogy, accessed September 16, 2019 .
  7. ↑ 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.  386 .
  8. ↑ Catalog of Type Mineral Specimens - K. (PDF 96 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed on September 16, 2019 (Kassite from p. 4).
  9. ^ Peter G. Self, Peter R. Buseck: Structure model for kassite, CaTi 2 O 4 (OH) 2 . In: American Mineralogist . tape 76 , 1991, pp. 283–287 (English, minsocam.org [PDF; 564 kB ; accessed on September 16, 2019]).
  10. ^ IE Gray, WG Mumme, IV Pekov, D. Yu. Pushcharovsky: The crystal structure of chromian kassite from the Saranovskoye deposit, Northern Urals, Russia . In: American Mineralogist . tape 88 , 2003, p. 1331–1335 (English, rruff.info [PDF; 429 kB ; accessed on September 16, 2019]).
  11. ↑ List of locations for Kassite in the Mineralienatlas and Mindat (accessed on September 16, 2019).