Garutiit
| Garutiit | |
|---|---|
| General and classification | |
| other names |
IMA 2008-055 |
| chemical formula | (Ni, Fe, Ir) |
|
Mineral class (and possibly department) |
elements |
| System no. according to Strunz | 1.AF.05 |
| Crystallographic Data | |
| Crystal system | hexagonal |
| Crystal class ; symbol | dihexagonal-dipyramidal; 6 / m 2 / m 2 / m |
| Space group | P 6 3 / mmc (No. 194) |
| Lattice parameters | a = 2.6939 Å ; c = 4.2732 Å |
| Formula units | Z = 2 |
| Physical Properties | |
| Mohs hardness | 6 (not defined) |
| Density (g / cm 3 ) | calculated: 11.33 (1) |
| Cleavage | is missing |
| colour | steel gray to gray black |
| Line color | black |
| transparency | opaque (opaque) |
| shine | Metallic luster |
Garutiite is a very rarely occurring mineral from the mineral class of the "elements (including natural alloys or intermetallic compounds, carbides, nitrides, phosphides and silicides)" with the chemical composition (Ni, Fe, Ir) and is therefore chemically a natural alloy , more precisely an intermetallic compound of nickel , iron and iridium .
Garutiite crystallizes in the hexagonal crystal system , but has so far only been discovered in the form of irregular to grape-shaped, porous grains ( crystallites ) up to about 110 μm. The mineral is opaque in every form and has a metallic sheen on the surfaces of the steel-gray to gray-black grains . In plane polarized light, gray appears white. However, his line color is always black.
Etymology and history
Garutiit was first discovered in 2008 during a heavy mineral analysis from the Loma Peguera open pit nickel mine ( 18 ° 59 ′ 24 ″ N , 70 ° 19 ′ 23 ″ W ) about 11 km northeast of Bonao in the Dominican Republic . It was first described in 2010 by a research team consisting of Andrew M. McDonald, Joaquin A. Proenza, Federica Zaccarini, Nikolay S. Rudashevsky, Louis J. Cabri, Chris J. Stanley, Vladimir N. Rudashevsky, Joan C. Melgarejo, John F. Lewis, Francisco Longo, and Ronald J. Bakker.
The name was chosen in honor of the Austrian professor Giorgio Garuti (* 1945) to honor his contributions to the understanding of the mineralogy of platinum group elements. The full mineral description and chosen name was submitted to the International Mineralogical Association (IMA) for review (IMA accession number : 2008-055 ) and approved in the year following the discovery.
Type material , i.e. mineral samples from its type locality Loma Peguera , are stored in the Mineralogical Museum of the Montan University Leoben in Austria under catalog no. 8241 kept.
classification
Since Garutiite was only recognized by the International Mineralogical Association (IMA) as an independent mineral in 2008 , it is not listed in the Strunz mineral system (8th edition), which has been outdated since 2001 . Only in Stefan Weiß's "Lapis Mineral Directory", which, out of consideration for private collectors and institutional collections, is still based on the classic system of Karl Hugo Strunz , was the mineral given system no. I / A.13-18 .
The 9th edition of Strunz's mineral systematics, introduced in 2001 by Strunz and Ernest Henry Nickel and used by the IMA, assigns Garutiit to the class of "elements" and there to the department of "metals and intermetallic compounds". This is further subdivided according to the predominant metals in the compound, which have been divided into metal families according to their related properties. According to its composition, Garutiit can be found in the subsection “Platinum Group Elements (PGE)”, where together with hexaferrum , osmium , rutheniridosmin and ruthenium, it forms the “ruthenium group” with system no. 1.AF.05 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Garutiit to the class of "elements" and there in the department of the same name. Here it is together with osmium, ruthenium, rutheniridosmin, hexaferrum and hexamolybdenum in the " osmium group (space group P6 3 / mmc) " with the system no. 02/01/02 within the sub-section “Elements: Platinum Group Metals and Alloys”.
Chemism
In a total of 42 analyzes on 27 grains using the electron microscope (see also electron microscope ), the chemical composition was 27.91% nickel (Ni), 19.94% iron (Fe), 43.78% iridium (Ir), 6.98% Platinum (Pt), 0.55% cobalt (Co), 0.43% copper (Cu), 0.50% ruthenium (Ru), 0.74% rhodium (Rh) and 0.67% osmium (Os) were determined (all data in% by weight). This corresponds to the empirical formula (Ni 0.421 Fe 0.316 Ir 0.202 Pt 0.032 Co 0.008 Cu 0.006 Rh 0.006 Ru 0.004 Os 0.003 ) Σ1 or simplified (Ni, Fe, Ir).
Crystal structure
Garutiit crystallizes hexagonally in the space group P 6 3 / mmc (space group no. 194) with the lattice parameters a = 2.6939 Å and c = 4.2732 Å as well as two formula units per unit cell .
Education and Locations
Garutiite is likely to form secondarily at low temperatures during postmagmatic processes such as serpentinization and / or lateritization .
At its type locality and so far the only known locality Loma Peguera (as of 2017) was Garutiit in the heavy mineral concentrates podiformer chromitite - deposits in Ophiolitic rocks discovered where he in paragenesis with Awaruit , ferrous chromite , various minerals of the chlorite and serpentine , Hexaferrum , Irarsit , Laurite as well as native ruthenium occurs.
See also
literature
- Andrew M. McDonald, Joaquin A. Proenza, Federica Zaccarini, Nikolay S. Rudashevsky, Louis J. Cabri, Chris J. Stanley, Vladimir N. Rudashevsky, Joan C. Melgarejo, John F. Lewis, Francisco Longo, Ronald J. Bakker : Garutiite, (Ni, Fe, Ir), a new hexagonal polymorph of native Ni from Loma Peguera, Dominican Republic . In: European Journal of Mineralogy . tape 22 , no. 2 , 2010, p. 293-304 , doi : 10.1127 / 0935-1221 / 2010/00222007 .
Web links
- Garutiit. In: Mineralienatlas Lexikon. Stefan Schorn u. a., accessed on May 2, 2020 .
- Garutiite. In: mindat.org. Hudson Institute of Mineralogy, accessed May 2, 2020 .
- American-Mineralogist-Crystal-Structure-Database - Garutiite. In: rruff.geo.arizona.edu. Retrieved May 2, 2020 .
Individual evidence
- ↑ a b c Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: March 2020. (PDF; 2.44 MB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, March 2020, accessed May 2, 2020 .
- ↑ a b c d e Andrew M. McDonald, Joaquin A. Proenza, Federica Zaccarini, Nikolay S. Rudashevsky, Louis J. Cabri, Chris J. Stanley, Vladimir N. Rudashevsky, Joan C. Melgarejo, John F. Lewis, Francisco Longo, Ronald J. Bakker: Garutiite, (Ni, Fe, Ir), a new hexagonal polymorph of native Ni from Loma Peguera, Dominican Republic . In: European Journal of Mineralogy . tape 22 , no. 2 , 2010, p. 293-304 , doi : 10.1127 / 0935-1221 / 2010 / 0022-2007 .
- ↑ 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 .
- ↑ Peter A. Williams, Frédéric Hatert, Marco Pasero, Stuart Mills: New Minerals approved in 2009 by IMA / CNMNC. (PDF; 186 kB) In: cnmnc.main.jp. IMA / CNMNC, 2009, accessed May 2, 2020 .
- ↑ Garutiite . 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; 189 kB ; accessed on January 9, 2018]).
- ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF; 1.82 MB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed May 2, 2020 .
- ↑ Find location list for Garutiit in the Mineralienatlas and Mindat , accessed on May 2, 2020.