Vanity

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Vanity
Eitelite-450589.jpg
Eitelite from the Westvaco Pit in the Green River Formation , Wyoming , USA (size 3.5 cm × 1.4 cm × 1.1 cm)
General and classification
chemical formula Na 2 Mg [CO 3 ] 2
Mineral class
(and possibly department) 		Carbonates and nitrates (formerly carbonates, nitrates and borates)
System no. to Strunz
and to Dana 		5.AC.05 ( 8th edition : Vb / A.05)
03/14/02/01
Crystallographic Data
Crystal system trigonal
Crystal class ; symbol trigonal-rhombohedral; 3
Space group R 3 (No. 148)Template: room group / 148
Lattice parameters a  = 4.94  Å ; c  = 16.41 Å
Formula units Z  = 3
Frequent crystal faces {10 1 1}, {01 1 2}, {0001}
Physical Properties
Mohs hardness 3.5
Density (g / cm 3 ) measured: 2.737; calculated: 2.732
Cleavage very perfect after {0001}
colour colorless, white
Line color White
transparency transparent
shine Glass gloss
Crystal optics
Refractive indices n ω  = 1.605
n ε  = 1.450
Birefringence δ = 0.155
Optical character uniaxial negative

Eitelite is a very seldom occurring mineral from the mineral class of " carbonates and nitrates " with the chemical composition Na 2 Mg [CO 3 ] 2 and thus chemically a sodium - magnesium carbonate.

Eitelite crystallizes in the trigonal crystal system and develops mostly transparent crystals of incomplete rhombohedral or pseudo- octahedral shape up to about 17 mm in size. The surface of the colorless to white, occasionally pale yellow crystals shows a glass-like sheen .

Etymology and history

Eitelit was first discovered in the Green River Formation , some 2,800 feet deep in the excavations of the Carter Oil Company Poulson No. 1 "in Duchesne County in the US state of Utah and described in 1954 by C. Milton, JM Axelrod and FS Grimaldi, who named the mineral after the director of the Institute for Silicate Research at the University of Toledo (Ohio, USA) Wilhelm Hermann Julius Eitel (1891– 1979) named.

classification

In the outdated 8th edition of the mineral classification according to Strunz , Eitelite still belonged to the common mineral class of "carbonates, nitrates and borates" and there to the department of "anhydrous carbonates without foreign anions ", where together with Sahamalith he formed the "Eitelite-Sahamalith group" with the system no. Vb / A.05 and the other members Burbankit , Bütschliit , Carbocernait , Fairchildit , Nyerereit and Shortit .

In the Lapis mineral directory according to Stefan Weiß, which, out of consideration for private collectors and institutional collections, is still based on this classic system of Karl Hugo Strunz , the mineral was given the system and mineral number. V / B.05-10 . In the "Lapis system" this also corresponds to the section "Anhydrous carbonates [CO 3 ] 2- , without foreign anions", where Eitelite, together with Bütschliit, Fairchildite, Gregoryite , Juangodoyite , Nyerereit, Shortite and Zemkorite, form an independent but unnamed group forms (as of 2018).

The 9th edition of Strunz's mineral systematics, valid since 2001 and updated by the International Mineralogical Association (IMA) until 2009, assigns the Eitelite to the newly defined class of “carbonates and nitrates” (the borates form a separate class here), there however also in the section of “Carbonates without additional anions; without H 2 O “. However, this is further subdivided according to the membership of the metals involved in certain element groups , so that the mineral according to its composition can be found in the sub-section "Alkali and alkaline earth carbonates", where it is the only member of the unnamed group 5.AC.05 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Eitelit, like the outdated 8th edition of Strunz's mineral systematics, to the common class of "carbonates, nitrates and borates" and there to the department of "anhydrous carbonates". Here he is to be found as the only member of the unnamed group 14.03.02 within the subdivision of " Anhydrous carbonates with a compound formula A 2+ B 2+ (CO 3 ) 2 ".

Crystal structure

Eitelit crystallizes trigonal in the space group R 3 (space group no. 148) with the lattice parameters a  = 4.94  Å and c  = 16.41 Å as well as 3 formula units per unit cell . Template: room group / 148

Education and Locations

Eitelite forms in dolomitic shale and in bituminous marl . Accompanying minerals include crocidolite , leukosphenite , nahcolith , northupite , reed mergnerite , searlesite , shortite and trona .

As a rare mineral formation, Eitelite could only be detected at a few sites, although a little more than 20 sites have been documented (as of 2019). In addition to its type locality "Carter Oil Company Poulson No. 1 ”the mineral occurred in the United States in the Indian Canyon and the Green River Formation as well as in the wells“ Joseph Smith No. 1 ” . 1 "," Mapco Shrine Hospital No. 1 "and" Marine Minerals No. 2 ”in Duchesne County , Utah and the Westvaco Mine in the Green River Formation in Sweetwater County, Wyoming.

Other well-known sites are among others

See also

literature

  • C. Milton, JM Axelrod, FS Grimaldi: New minerals, reedmergnerite (Na 2 O · B 2 O 3 · 6SiO 2 ) and eitelite (Na 2 O · MgO · 2CO 2 ) associated with leucosphenite, shortite, searlesite, and crocidolite in the Green River formation, Utah . In: American Mineralogist . tape 40 , 1955, pp. 326–327 (English, rruff.info [PDF; 183 kB ; accessed on September 29, 2019]).
  • Adolf Pabst: The Crystallography and Structure of Eitelite, Na 2 Mg (CO 3 ) 2 . In: American Mineralogist . tape 58 , 1973, p. 211–217 (English, minsocam.org [PDF; 815 kB ; accessed on September 29, 2019]).
  • D. Knobloch, F. Pertlik, Josef Zemann : Crystal structure refinements of buetschliite and eitelite: a contribution to the stereochemistry of trigonal carbonate minerals . In: New yearbook for mineralogy, monthly books . tape 5 , 1980, pp. 230-236 (English).
  • Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 577 (first edition: 1891).

Web links

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

Individual evidence

  1. ↑ a b c d e 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.  290 (English).
  2. ↑ a b David Barthelmy: Mineral Data. In: webmineral.com. Retrieved September 29, 2019 .
  3. ↑ a b c d Eitelite . 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; 68  kB ; accessed on September 29, 2019]).
  4. ↑ a b c Eitelite. In: mindat.org. Hudson Institute of Mineralogy, accessed September 29, 2019 .
  5. ↑ Eitelite - Photo Gallery. In: mindat.org. Hudson Institute of Mineralogy, accessed September 29, 2019 .
  6. ^ Adolf Pabst: The Crystallography and Structure of Eitelite, Na 2 Mg (CO 3 ) 2 . In: American Mineralogist . tape 58 , 1973, p. 211–217 (English, minsocam.org [PDF; 815 kB ; accessed on September 29, 2019]).
  7. ↑ 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 .
  8. ↑ 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 29, 2019 .
  9. ↑ Localities for Eitelite. In: mindat.org. Hudson Institute of Mineralogy, accessed September 29, 2019 .
  10. ↑ Find location list for Eitelite at the Mineralienatlas and at Mindat