Seeligerite
| Seeligerite | |
|---|---|
 |
|
| General and classification | |
| other names |
IMA 1970-036 |
| chemical formula | Pb 3 Cl 3 O (IO 3 ) |
|
Mineral class (and possibly department) |
Oxides and hydroxides (formerly halides) |
|
System no. to Strunz and to Dana |
4.KB.15 ( 8th edition : III / D.10) 01/22/02/01 |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-disphenoidic; 222 |
| Space group | C 222 1 (No. 20) |
| Lattice parameters | a = 7.96 Å ; b = 7.96 Å; c = 27.29 Å |
| Formula units | Z = 8 |
| Physical Properties | |
| Mohs hardness | Please complete |
| Density (g / cm 3 ) | measured: 6.83 (synthetic); calculated: 7.052 |
| Cleavage | good after {001} and {110}; indistinct after {100} and {010} |
| colour | light yellow |
| Line color | pale yellow |
| transparency | translucent |
| shine | Glass gloss, wax gloss |
| Crystal optics | |
| Refractive indices |
n α = 2.120 n β = 2.320 n γ = 2.320 |
| Birefringence | δ = 0.200 |
| Optical character | biaxial negative |
| Axis angle | 2V = 4 ° |
Seeligerite is a very rare mineral from the mineral class of "oxides and hydroxides" (formerly halides ) with the chemical composition Pb 3 Cl 3 O (IO 3 ) and is therefore chemically a lead - chlorine - iodate .
Seeligerite crystallizes in the orthorhombic crystal system and develops mostly pseudo-tetragonal, square crystal platelets of light yellow color with a wax- to glass-like sheen on the surfaces.
Etymology and history
Seeligerite was first discovered in the Santa Ana mine in the Caracoles mining area (Sierra Gorda district) in the Chilean region of Antofagasta . The mineral was described in 1971 by Arno Mücke (* 1937), who named it after Erich Seeliger, Professor of Mineralogy at the Technical University of Berlin .
classification
In the outdated, but partly still in use, 8th edition of the mineral classification according to Strunz , the seeligerite belonged to the mineral class of "halides" and there to the department of "oxyhalides", where together with asisite , blixite , damaraite , ekdemite , heliophyllite , kombatite , mendipite , Mereheadit , Nadorit , Parkinsonit , Penfieldit , Perit , Philolithit , Pinalit , Sahlinit , Schwartzembergit , Sundiusit , Symesit , Thorikosit the "Mendipite-Nadorit group" with the system number. III / D.10 .
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), assigns the Seeligerite to the class of "oxides and hydroxides" and there to the category of "iodates" related to oxides. This is further subdivided according to the possible presence of further anions and water of crystallization , so that the mineral is classified according to its composition in the sub-section “Iodates with additional anions; without H 2 O “can be found, where it is the only member of the unnamed group 4.KB.15 .
According to Dana, the mineral system , which is mainly used in the English-speaking world, classifies the Seeligerite in a different way . Here he is in the class of "Carbonates, Nitrates and Borates" and the department of "Iodates - hydroxyls or halogens", where he is the only member of the unnamed group 01/22/02 within the subdivision " Iodates - hydroxyls or halogens with different Formulas ”.
Crystal structure
Seeligerite crystallizes orthorhombically in space group C 222 1 (space group no. 20) with the lattice parameters a = 7.96 Å ; b = 7.96 Å and c = 27.29 Å as well as 8 formula units per unit cell .
Education and Locations
Seeligerite forms secondarily in the oxidation zone of hydrothermal , polymetallic deposits . The accompanying minerals include Boleit , Paralaurionite (also Rafaelite ) and Schwartzembergite .
So far, Seeligert could only be found in Chile. In addition to its type of locality , the Santa Ana mine and other pits in the mining area around Caracoles and Magallanes in the Antofagasta region , the mineral is also known from the Lolon mine near Challacollo in the Tamarugal province ( Tarapacá region ).
See also
literature
- Arno Mücke: Seeligerite, a natural lead iodate In: New Yearbook for Mineralogy MONTHS, 1971, pp. 210–217 (available online at researchgate.net )
- Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 562 (first edition: 1891).
- L. Bindi, MD Welch, P. Bonazzi, G. Pratesi, S. Menchetti: The crystal structure of seeligerite, Pb 3 IO 4 Cl 3 , a rare Pb-I-oxychloride from the San Rafael mine, Sierra Gorda, Chile In : Mineralogical Magazine Volume 72 (2008), pp. 771–783 ( PDF 2.2 MB )
Web links
- Mineral Atlas: Seeligerite (Wiki)
- RRUFF Database-of-Raman-spectroscopy - Seeligerite
- American-Mineralogist-Crystal-Structure-Database - Seeligerite
Individual evidence
- ↑ a b c d 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 .
- ↑ Webmineral - Seeligerite
- ↑ a b Seeligerite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF kB )
- ↑ a b c d e f Mindat - Seeligerite
- ↑ Michael Fleischer: New Mineral Names In: The American Mineralogist Volume 57 (1972), pp. 325–329 ( PDF 350.9 kB ; Seeligerit from p. 3)
- ↑ Find location list for Seeligerite at the Mineralienatlas and at Mindat