Monteponite

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Monteponite
Monteponite.jpg
Monteponite (black, center) from the volcano Kudrjawy , Kuril island Iturup, Russian federal district Far East
General and classification
other names

Genaruttit

chemical formula CdO
Mineral class
(and possibly department) 		Oxides and hydroxides
System no. to Strunz
and to Dana 		4.AB.25 ( 8th edition : IV / A.04)
02/04/01/04
Crystallographic Data
Crystal system cubic
Crystal class ; symbol cubic hexakisoctahedral; 4 / m  3  2 / m
Space group Fm 3 m (No. 225)Template: room group / 225
Lattice parameters a  = 4.69  Å
Formula units Z  = 4
Twinning Penetrating twins, unknown twin law
Physical Properties
Mohs hardness 3
Density (g / cm 3 ) measured: 8.1 to 8.2 (synthetic); calculated: 8.238
Cleavage after {111}
colour black; red to orange-brown in transmitted light
Line color black
transparency transparent
shine Metallic luster
Crystal optics
Refractive indices n α  = 2.49 (Li)
Other properties
Chemical behavior soluble in dilute acids

Monteponite or genaruttite , chemically cadmium oxide , is a very rarely occurring mineral from the mineral class of oxides and hydroxides . It crystallizes in the cubic crystal system with the chemical composition CdO and forms black, octahedral crystals up to 0.05 mm in size , which were found in a druse . Powders and masses of the mineral were also found.

Etymology and history

The mineral was first discovered on a handpiece from Monte Poni near Iglesias on the Italian island of Sardinia . It was first described in 1901 by E. Wittich and B. Neumann, who expressly did not give cadmium oxide their own mineral name, as they considered the chemical name to be the simplest and clearest.

The mineral name Monteponite, which is still valid today, was first coined in 1946 by Ernest E. Fairbanks, who chose the name based on its type locality .

classification

Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , monteponite belonged to the mineral class of "oxides and hydroxides" and there to the division of "oxides with a metal: oxygen ratio = 1: 1 and 2: 1 (M 2 O, MO) ", where together with bunsenite , calcium oxide , manganosite , murdochite , periclase and wüstite the" periclase group "with the system no. IV / A.04 .

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 monteponite in the category of "oxides with a metal: oxygen ratio = 2: 1 and 1: 1". However, this is further subdivided according to the exact molar ratio and the relative size of the cations involved , so that the mineral is classified according to its composition in the subsection “Cation: Anion (M: O) = 1: 1 (and up to 1: 1.25); with only small to medium-sized cations "can be found, where together with bunsenite, calcium oxide, ferropericlass (Q), manganosite, periclase and wüstite, the" periclase group "with the system no. 4.AB.25 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns monteponite to the class of "oxides and hydroxides" and there in the department of "oxides". Here he is the only member / together with in the "Periclas Group (Isometric, Fm3m)" with the system no. 04.02.01 to be found within the subsection “ Simple oxides with a cation charge of 2+ (AO) ”.

Crystal structure

Crystal structure of monteponite

Monteponite crystallizes in the cubic crystal system with the space group Fm 3 m (space group no. 225) with the lattice parameter a  = 4.69  Å and four formula units per unit cell (sodium chloride structure). Template: room group / 225

Education and Locations

Monteponite very rarely forms as a coating over smithsonite or hemimorphite , as well as in sulfidic ores. Depending on where it was found, it is associated with smithsonite and hemimorphite or cadmium and otavite .

In addition to the type locality, finds of monteponite are only known from Duyun in China , Laurion in Greece and Verkhoyansk and Iturup in Russia .

See also

literature

  • E. Wittich, B. Neumann: A new cadmium mineral . In: Centralblatt für Mineralogie, Geologie und Paläontologie . 1901, p. 549–551 ( available online at archive.org  - Internet Archive [accessed December 2, 2018]).
  • Richard V. Gaines, H. Catherine W. Skinner, Eugene E. Foord, Brian Mason , Abraham Rosenzweig: Dana's New Mineralogy . 8th edition. John Wiley & Sons, New York (et al.) 1997, ISBN 0-471-19310-0 , pp. 210 .
  • Marco E. Ciriotti, Lorenza Fascio, Marco Pasero: Italian Type Minerals . 1st edition. Edizioni Plus - Università di Pisa, Pisa 2009, ISBN 978-88-8492-592-3 , p. 193 .

Web links

Commons : Monteponite  - 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.  185 (English).
  2. ↑ a b c d Monteponite . 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; 60  kB ; accessed on December 2, 2018]).
  3. ^ A b Richard V. Gaines, H. Catherine W. Skinner, Eugene E. Foord, Brian Mason , Abraham Rosenzweig: Dana's New Mineralogy . 8th edition. John Wiley & Sons, New York (et al.) 1997, ISBN 0-471-19310-0 , pp. 210 .
  4. ↑ Mindat - Genaruttit, German synonym of Monteponite (English)
  5. ^ E. Wittich, B. Neumann: A new cadmium mineral . In: Centralblatt für Mineralogie, Geologie und Paläontologie . 1901, p. 549–551 ( available online at archive.org  - Internet Archive [accessed December 2, 2018]).
  6. ↑ Michael Fleischer : New Mineral Names . In: American Mineralogist . tape  32 , 1947, pp. 484 (English, minsocam.org [PDF; 186 kB ; accessed on December 2, 2018]).
  7. ↑ List of localities for monteponite in the Mineralienatlas and Mindat