Laueit
| Laueit | |
|---|---|
 |
|
| General and classification | |
| chemical formula | Mn 2+ Fe 2 3+ [OH | PO 4 ] 2 · 8H 2 O |
|
Mineral class (and possibly department) |
Phosphates, arsenates and vanadates |
|
System no. to Strunz and to Dana |
8.DC.30 ( 8th edition : VII / D.10) 11.42.10.01 |
| Crystallographic Data | |
| Crystal system | triclinic |
| Crystal class ; symbol | triclinic pinacoidal; 1 |
| Space group | P 1 (No. 2) |
| Lattice parameters |
a = 5.28 Å ; b = 10.66 Å; c = 7.14 Å, α = 107.9 °; β = 111.0 °; γ = 71.1 ° |
| Formula units | Z = 1 |
| Frequent crystal faces | {100}, {010}, {001}, {110}, {1 1 0}, {0 1 1}, {011} |
| Physical Properties | |
| Mohs hardness | 3 |
| Density (g / cm 3 ) | measured: 2.44 to 2.49; calculated: 2.56 |
| Cleavage | completely after {010} |
| Break ; Tenacity | very brittle |
| colour | honey brown, amber, yellow to dark yellow, yellow orange to reddish orange |
| Line color | White |
| transparency | transparent to translucent |
| shine | Glass gloss |
| Crystal optics | |
| Refractive indices |
n α = 1.588 to 1.603 n β = 1.654 to 1.659 n γ = 1.680 to 1.682 |
| Birefringence | δ = 0.092 |
| Optical character | biaxial negative |
| Axis angle | 2V = 63 to 66 ° (measured); 62 ° (calculated) |
Laueit is a rarely occurring mineral from the mineral class of " phosphates , arsenates and vanadates ". It crystallizes in the triclinic crystal system with the chemical composition Mn 2+ Fe 2 3+ [OH | PO 4 ] 2 · 8H 2 O and is therefore chemically a water-containing manganese - iron phosphate with additional hydroxide ions .
Laueit develops transparent to translucent crystals up to about three millimeters in size with a tabular to prismatic habit and a glass-like sheen on the surfaces. Its color varies from honey to amber brown or yellow to reddish orange, but its line color is always white.
Etymology and history
Laueit was first discovered in the Cornelia mine near Hagendorf-Süd / Waidhaus in the Upper Palatinate Forest in Bavaria and described in 1954 by Karl Hugo Strunz , who named the mineral after the German physicist and Nobel Prize winner Max von Laue .
classification
In the outdated, but still in use 8th edition of the mineral classification according to Strunz , the Laueit belonged to the mineral class of "phosphates, arsenates and vanadates" and there to the department of "water-containing phosphates with foreign anions ", where together with ferrolaueit , gordonite , mangangordonite , Paravauxite , Sigloit and Ushkovit the "Paravauxite group" with the system no. VII / D.10 formed.
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 assigns the Laueit to the class of "phosphates, arsenates and vanadates" and there to the department of "phosphates, etc. with additional anions ; with H 2 O “. However, this section is further subdivided according to the size of the cations involved and the ratio of the additional anions to the cation complex RO 4 , so that the mineral is classified in the sub-section “With only medium-sized cations; (OH etc.): RO 4 = 1: 1 and <2: 1 "can be found where the" Laueit group "with the system no. 8.DC.30 and the other members Ferrolaueit, Gordonit, Maghrebit ( IMA2005-044 ) Kastningit , Mangangordonit, paravauxite, Pseudolaueit , Sigloit, Stewartit forms and Ushkovit.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Laueit to the class of "phosphates, arsenates and vanadates" and there to the category of "water-containing phosphates, etc., with hydroxyl or halogen". Here he is also the namesake of the "Laueit Group" with the system no. 42.11.10 and the other members stewartite, pseudolaueit, ushkovite and ferrolaueit can be found within the subdivision of " water-containing phosphates etc., with hydroxyl or halogen with (AB) 4 (XO 4 ) 3 Z q × x (H 2 O) " .
Modifications and varieties
The compound Mn 2+ Fe 2 3+ [OH | PO 4 ] 2 · 8H 2 O is trimorphic and occurs naturally in addition to the triclinic laueity as a monoclinic crystallizing pseudolaueity and also as a triclinic crystallizing stewartite , however with different lattice parameters .
Education and Locations
Laueit formed hydrothermally in oxidized triphylinhaltigen granite - pegmatites . The accompanying minerals include ludlamite , pseudolaueit, rockbridgeit , siderite , stewartite and strunzite .
As a rare mineral formation, Laueit has only been able to prove a few sites, with around 70 sites being known. In addition to its type locality "Grube Cornelia" near Hagendorf-Süd / Waidhaus , the mineral also appeared in Germany in the Silbergrube, also located near Waidhaus, at the Hühnerkobel near Zwiesel in Bavaria and in the Clara mine near Oberwolfach in Baden-Württemberg.
Other locations include Argentina, Australia, Brazil, Finland, France, Italy, Namibia, Portugal, Russia, Sweden, the Czech Republic, and the United States of America (USA).
Crystal structure
Laueit crystallizes isotypically with gordonite in the triclinic crystal system in the space group P 1 (space group no. 2) with the lattice parameters a = 5.28 Å ; b = 10.66 Å; c = 7.14 Å; α = 107.9 °; β = 111.0 ° and γ = 71.1 ° and one formula unit per unit cell .
See also
literature
- H. Strunz: Laueit, MnFe 2 3+ [OH | PO 4 ] 2 · 8H 2 O, a new mineral. In: The natural sciences. Volume 41, Chapter 11, 1954, pp. 256-256 doi: 10.1007 / BF00634947
- Hans Jürgen Rösler : Textbook of Mineralogy . 4th revised and expanded edition. German publishing house for basic industry (VEB), Leipzig 1987, ISBN 3-342-00288-3 , p. 641 .
- Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 648 (first edition: 1891).
Web links
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. 500 .
- ↑ Webmineral - Laueite
- ↑ a b c d Laueite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 66.6 kB )
- ↑ a b c d e f Mindat - Laueite
- ↑ Mindat - Number of localities for Laueit