Tarasovite

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Tarasovite
General and classification
chemical formula
  • (Na, K, H 3 O, Ca) 2 Al 4 [(OH) 2 | (Si, Al) 4 O 10 ] 2 ∙ H 2 O
  • (Na, K, Ca) Al 4 [(OH) 2 | (Si, Al) 4 O 10 ] 2 ∙ H 2 O (?)
  • K, Mg, Al, Si, O, H 2 O
Mineral class
(and possibly department) 		Silicates - layered silicates
System no. according to Strunz none, as not recognized
Crystallographic Data
Crystal system monoclinic
Crystal class ; symbol not defined
Lattice parameters a  = 5.13  Å ; b  = 8.88 Å; c  => 19.7 Å
β  = 95.0 °
Physical Properties
Mohs hardness 1-2
Density (g / cm 3 ) not defined
Cleavage perfectly
colour white, pink, sometimes colorless
Line color White
transparency translucent
shine Glass gloss

Tarasovite is a rare mineral from the mica group that is not recognized by the International Mineralogical Association (IMA) and has the approximate chemical composition K, Mg, Al, Si, O, H 2 O.

Etymology and history

Was first discovered tarasovite in the 1960s in the form of scaly aggregates in the hall bands of quartz - transitions in sandy shale of the middle Carboniferous , which near the Ukrainian village Naholno-Tarassiwka in the Donets Basin occur.

The first description was in 1970 by the geologist, mineralogist and rector of Lviv University Jewhen Lasarenko (English Lazarenko ) and Yu. M. Korolev. Tarasovit was named after the Ukrainian national poet Taras Shevchenko (English: Taras Grigorievich Shevchenko ).

The Tarasovite type material is kept in the Mineralogical Museum of the Russian Academy of Sciences in Moscow .

Chemism

After the first analyzes of the chemical composition and structure, Lasarenko and Korolev assumed that Tarasovit is a di- octahedral interlayer mineral with the empirical formula (Ca 0.18 Na 0.24 ) exch (Na 1.00 K 1, 18 (H 3 O) 0.61 ) (Si 12.85 Al 3.35 ) O 40 Al 8 (OH) 8 · 2H 2 O. This corresponds to the crystal chemical structural formula (Na, K, H 3 O, Ca) 2 Al 4 [(OH) 2 | (Si, Al) 4 O 10 ] 2 ∙ H 2 O.

The interstratification of mica layers and rectorite , initially regarded as regular, was referred to as "MMMS", i. H. the sequence of layers would therefore consist of three layers of mica (English mica ) and one dioctahedral smectite layer (S). However, since the degree of regularity was not sufficient to justify an independent mineral type, Tarasovit was discredited in 1981.

literature

  • SW Bailey: A system of nomenclature for regular interstratifications . In: The Canadian Mineralogist . tape 19 , no. 4 , 1981, p. 651–655 , doi : 10.1180 / claymin.1982.017.2.09 (English, pubs.geoscienceworld.org [PDF; accessed on September 22, 2019]).
  • George William Brindley, Tetsuya Suzuki: Tarasovite, a mixed-layer illite-smectite which approaches an ordered 3: 1 layer ratio . In: Clay Minerals . tape 18 , no. 1 , 1983, p. 89–94 , doi : 10.1180 / claymin.1983.018.1.08 (English).

Web links

Individual evidence

  1. ↑ a b Tarasovite. In: Mineralienatlas Lexikon. Stefan Schorn u. a., accessed on September 22, 2019 .
  2. ↑ 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 .
  3. ↑ a b c Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed September 22, 2019 .
  4. ^ 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.  674 (English).
  5. ↑ a b c Tarasovite. In: leksika.com.ua. Soviet Ukrainian Encyclopedia , accessed September 22, 2019 (Ukrainian).
  6. ^ A b c Michael Fleischer : New Mineral Names . In: The American Mineralogist . tape  56 , no. 5-6 , 1971, pp. 1123 (English, minsocam.org [PDF; 217 kB ; accessed on September 22, 2019]).
  7. ↑ Tarasovite. In: mindat.org. Hudson Institute of Mineralogy, accessed September 22, 2019 .