Ferberite
| Ferberite | |
|---|---|
 |
|
| General and classification | |
| chemical formula | FeWO 4 or Fe 2+ WO 4 |
|
Mineral class (and possibly department) |
Oxides and hydroxides |
|
System no. to Strunz and to Dana |
4.DB.30 ( 8th edition : IV / D.16) 01/48/01/02 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Space group | P 2 / c (No. 13) |
| Lattice parameters |
a = 4.72 Å ; b = 5.70 Å; c = 4.96 Å β = 90 ° |
| Formula units | Z = 2 |
| Physical Properties | |
| Mohs hardness | 4 to 4.5 |
| Density (g / cm 3 ) | measured: 7.58; calculated: 7.60 |
| Cleavage | completely after {010}; Secretions according to {100} and {102} |
| Break ; Tenacity | uneven; brittle |
| colour | black |
| Line color | brown-black to black |
| transparency | opaque, almost opaque |
| shine | Metallic luster |
| Crystal optics | |
| Refractive indices |
n α = 2.255 n β = 2.305 n γ = 2.414 |
| Birefringence | δ = 0.159 |
| Optical character | biaxial positive |
| Axis angle | 2V = 66 ° |
Ferberite is a rather seldom occurring mineral from the mineral class of " oxides and hydroxides " with the chemical composition FeWO 4 and is therefore, from a chemical point of view, iron tungstate .
Ferberite crystallizes in the monoclinic crystal system and develops mainly short, prismatic to tabular crystals , but also occurs in the form of granular to massive aggregates . The almost non-transparent ( opaque ) crystals are black in color with a metallic sheen on the surfaces. The mineral leaves a brown-black to black line on the marking board .
Ferberite is one of the final links of wolframite - mixed batch , the other end link Hübnerit forms.
Etymology and history
.jpg)
The mineral was named after Moritz Rudolph Ferber (1805–1875), a German amateur mineralogist from Gera. It was first found and described in 1863.
classification
In the meanwhile outdated, but still in use 8th edition of the mineral classification according to Strunz , the ferberite belonged to the department of "oxides with the molar ratio metal: oxygen = 1: 2 (MO 2 and related compounds)", where together with Huebnerite , Sanmartinite and the now discredited Wolframo-Ixiolit the " Wolframit -series" with the system no. IV / D.16 .
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 Ferberit in the department of "Oxides with a metal: oxygen ratio of 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 medium-sized cations; Chains of edge-linked octahedra "can be found, where together with Heftetjernite , Huebnerite, Krasnoselskite, Magnesiowolframit and Sanmartinit the" Wolframite group "with the system no. 4.DB.30 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking area , assigns ferberite, in contrast to Strunz's systematics, to the class of "phosphates, arsenates, vanadates" and there in the department of "molybdates and wolframates". Here it is together with Wolframite, Huebnerite, Sanmartinite and Heftetjernit in the "Wolframite series" with the system no. 48.01.01 to be found in the subsection of " Anhydrous molybdates and tungstates with A XO 4 ".
Crystal structure
Ferberite crystallizes monoclinically in the space group P 2 / c (space group no. 13) with the lattice parameters a = 4.72 Å , b = 5.70 Å and c = 4.96 Å; β = 90 ° and two formula units per unit cell .
Education and Locations
Ferberite is formed either by hydrothermal processes in greisen or in skarns or in igneous rocks such as pegmatites or granites . Accompanying minerals are cassiterite , quartz , scheelite and various sulphides .
Locations include Tamanrasset in Algeria ; New South Wales , Queensland , South Australia , Tasmania and Victoria in Australia ; various provinces in Bolivia , Brazil , the People's Republic of China ; Baden-Württemberg , Lower Saxony , Saxony and Saxony-Anhalt in Germany ; New Brunswick , Nova Scotia and Yukon in Canada ; Maniema in the Democratic Republic of the Congo ; Carinthia and Salzburg in Austria ; Bohemia and Moravia in the Czech Republic ; as well as Arizona , Arkansas , Colorado , Connecticut , California and other states in the United States .
use
Ferberite is an important ore for the extraction of tungsten .
See also
literature
- KL Th. Liebe: A new wolframite . In: New Yearbook for Mineralogy, Geology and Paleontology . 1863, pp. 641-653 ( PDF 554.2 kB ).
- Petr Korbel, Milan Novák: Encyclopedia of Minerals . Nebel Verlag GmbH, Eggolsheim 2002, ISBN 3-89555-076-0 , p. 105 .
Web links
- Mineral Atlas: Ferberite (Wiki)
- RRUFF Database-of-Raman-spectroscopy - Ferberite
- American-Mineralogist-Crystal-Structure-Database - Ferberite
Individual evidence
- ↑ 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. 210 .
- ↑ Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties . 6th completely revised and supplemented edition. Weise, Munich 2014, ISBN 978-3-921656-80-8 .
- ↑ Webmineral - Ferberite (English)
- ↑ a b c d Ferberite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 65.6 kB )
- ↑ a b c d e f Mindat - Ferberite (Engl.)
- ↑ Find location list for Ferberite at the Mineralienatlas and at Mindat