Palygorskit
| Palygorskit | |
|---|---|
 Size: 2.75 "× 1.5" × 1.5 "; corresponds to ≈ 7 cm × 3.8 cm × 3.8 cm |
|
| General and classification | |
| other names |
|
| chemical formula | (Mg, Al) 4 [OH | (Si, Al) 4 O 10 ] 2 • (4 + 4) H 2 O |
|
Mineral class (and possibly department) |
Layered silicates (phyllosilicates) |
|
System no. to Strunz and to Dana |
9.EE.20 ( 8th edition : VIII / H.33) 74.03.01a.01 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Space group | C 2 / m (No. 12) |
| Lattice parameters |
a = 12.70 Å ; b = 17.83 Å; c = 5.24 Å β = 95.8 ° |
| Formula units | Z = 2 |
| Frequent crystal faces | flattened after {100} |
| Physical Properties | |
| Mohs hardness | 2 to 2.5 |
| Density (g / cm 3 ) | measured:> 1.0 to 2.6; calculated: [2.35] |
| Cleavage | good after {110} |
| Break ; Tenacity | uneven |
| colour | white, grayish, yellowish, gray-green; colorless in thin layers |
| Line color | White |
| transparency | translucent to opaque |
| shine | Wax gloss, silk gloss, earthy matt |
| Crystal optics | |
| Refractive indices |
n α = 1.522 to 1.528 n β = 1.530 to 1.546 n γ = 1.533 to 1.548 |
| Birefringence | δ = 0.011 to 0.020 |
| Optical character | biaxial negative |
| Axis angle | 2V = 30 to 61 ° |
| Pleochroism | visible: X = light yellow; Y = Z = light yellow green |
The mineral palygorskite , outdated as mountain leather , mountain cork , mountain wood or mountain meat as well as attapulgite known, a layer silicate with the chemical composition (Mg, Al) 4 [OH | (Si, Al) 4 O 10 ] 2 * (4 + 4 ) H 2 O. The elements magnesium and aluminum or silicon and aluminum indicated in the round brackets can represent each other in the formula ( substitution , diadochie), but are always in the same proportion to the other components of the mineral.
It crystallizes in the monoclinic crystal system and forms translucent to opaque, mostly needle-like crystals , but also fibrous to massive aggregates of white, grayish to yellowish or gray-green color. In thin layers it can also be colorless. Visible crystal surfaces and fibrous aggregates have a wax-like sheen , the massive aggregates, on the other hand, are more earthy matt.
It may be abundant at individual sites, but overall it is not very common.
Etymology and history
Palygorskite was first discovered in the so-called "Second Mine" on the Popowka River near Palygorsk in the Urals in the Russian region of Perm . The mineral was first described in 1862 by TV Savchenkov, who named it after its type locality .
The mineral got its synonymous name attapulgite after a discovery near the city of Attapulgus in Georgia, USA.
classification
In the meantime outdated, but still in use 8th edition of the mineral classification by Strunz of palygorskite belonged to the mineral class of "silicates and Germanates" and then to the Department of "phyllosilicates (phyllosilicates)" where he collaborated with Falcondoit , Kalifersit , Loughlinit , sepiolite , Tuperssuatsiait and Yofortierit formed the unnamed group VIII / H.33 .
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 palygorskite to the class of "silicates and germanates" and there in the department of "phyllosilicates". However, this section is further subdivided according to the structure of the silicate layers, so that the mineral can be found according to its structure in the sub-section “Simple tetrahedral networks of 6-membered rings, connected by octahedral networks or bands”, where it can only be found together with Tuperssuatsiaite and Yofortierit forms the unnamed group 9.EE.20 .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the palygorskite to the class of "silicates and Germanates" and there in the department of "layered silicates: modulated layers". Here he is the only member / together with Kalifersit, Tuperssuatsiait and Yofortierit in the "Palygorskit-Sepiolitegruppe (Palygorskit-Untergruppe)" with the system no. 74.03.01a can be found in the subsection " Layered Silicates: Modulated Layers with Connected Stripes ".
Crystal structure
Palygorskite crystallizes monoclinically in the space group C 2 / m (space group no. 12) with the lattice parameters a = 12.70 Å ; b = 17.83 Å; c = 5.24 Å and β = 95.8 ° and two formula units per unit cell .
properties
Part of its crystal water is firmly bound as constitution water (also structural water ), while another part is only loosely stored in a “ zeolitic ” manner. When heated to 220 ° C, up to 15% of this can gradually be released.
Education and Locations
Palygorskite forms hydrothermally in various rocks such as granite , marble or serpentinite .
So far (as of 2012) 265 sites for palygorskite are known worldwide. In addition to its type locality "Second Mine" near Palygorsk , the mineral also appeared in Russia in the Sakara mine, which is also located in the Urals, the Cheremshanskoe mine and the Sinar and Akkermanovskoe deposits. The mineral was also found in the Sakha Republic ( Yakutia ), near Kawalerowo , on the Kola Peninsula and in the Volga region.
In Germany, the mineral could so far only be found near Marktredwitz (Ziegelhütte), in several places near Wunsiedel and on the Zeilberg in Bavaria. The most recent location is Trebur in Hesse , where palygorskite was encountered while sinking a geothermal well .
In Austria, palygorskit has so far mainly been found in Carinthia , Salzburg and Styria (Friesach-Hüttenberg, Frauenkogel, Gailtaler Alpen, Hohe Tauern, Koralpe, Oberdorf an der Laming), but also near Atzelsdorf ( Brunn an der Wild ) in Lower Austria and near Mauthausen in Upper Austria.
In Switzerland, Palygorskit performed at Büren an der Aare (Bern), Entlebuch LU (Lucerne), Ennetbürgen and Stansstad (Nidwalden), Crissier (Waadt) and in the Binntal (Valais).
Other locations are in Australia, Bulgaria, Chile, China, Ecuador, France, Greenland, Iran, Iraq, Italy, Japan, Canada, Kazakhstan, Qatar, Kyrgyzstan, Madagascar, Morocco, Mexico, Namibia, Norway, Peru, Poland, Romania, Saudi Arabia, Sweden, Senegal, Slovakia, Slovenia, Spain, Czech Republic, Turkey, Ukraine, Hungary, Uzbekistan, the United Kingdom and the United States.
Uses
If palygorskite is on the surface, it is a reliable paleoclimate indicator as it is quickly converted to smectite under humid to semi-humid conditions .
In the case of strong local occurrences, palygorskite was used as heat or sound insulation material instead of asbestos .
Palygorskit is sold as an imitation gemstone under the trade name Angel-Skin-Opal due to its appearance similar to the opal (see also Gemstone ).
Researchers discovered a four-meter-thick layer of blue paint at the bottom of a well in Chichén Itzá , which the Maya used for human sacrifices to their rain god Chaac . Only chemists were able to clarify through experiments that the pigment called “ Mayan blue ” can be produced with the help of palygorskite and indigo , which are heated together.
In many countries attapulgite (e.g. in Indonesia as New Diatabs or in Canada as Kaopectate ) is approved and used as a remedy for diarrhea .
In Germany it is common in the field of veterinary medicine.
See also
literature
- TV Savchenkov: Palygorskit. In: Saint Petersburg: Negotiations of the Russian Imperial Society for Mineralogy. 1862, pp. 102-104 (reference 159 in F. Bergaya, G. Lagaly: Handbook of Clay Science in the Google book search)
- Erich Reiter: The mountain leather (palygorskit). In: Natural History Object of the Month. Biology Center Linz, February 2012 ( PDF (2 MB) on ZOBODAT ).
- Petr Korbel, Milan Novák: Encyclopedia of Minerals . Nebel Verlag GmbH, Eggolsheim 2002, ISBN 3-89555-076-0 , p. 260 ( Dörfler Natur ).
Web links
Individual evidence
- ↑ a b c d e Hugo Strunz , Ernest H. Nickel: Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X .
- ↑ Webmineral - palygorskite
- ↑ a b John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols: Palygorskite , in: Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 78.7 kB )
- ↑ a b c d e f g Mindat - Palygorskite
- ↑ a b c d Hans Jürgen Rösler : Textbook of Mineralogy . 4th revised and expanded edition. German publishing house for basic industry (VEB), Leipzig 1979, ISBN 3-342-00288-3 , p. 579 .
- ↑ Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties . 5th completely revised and supplemented edition. Weise, Munich 2008, ISBN 978-3-921656-70-9 .
- ↑ ÜWG: Erdwärme Groß-Gerau: Change in drilling path approved. In: www.geothermie-trebur.de. Retrieved July 12, 2016 .
- ^ Rüdiger Glaser , Klaus Kremb, Axel Drescher (eds.): Africa . 2nd, unchanged edition. Scientific Book Society, Darmstadt 2011, ISBN 978-3-534-24679-3 .
- ^ Walter Schumann: Precious stones and gemstones. All kinds and varieties. 1900 unique pieces . 16th revised edition. BLV Verlag, Munich 2014, ISBN 978-3-8354-1171-5 , pp. 234 .
- ↑ stern.de - Mystery of Maya blue revealed
- ↑ Antiquity Volume 82, pp. 151-164 (2008)
- ^ Ingredient matches for New Diatabs at drugs.com
- ↑ NEW DIATABS Tablet Antidiare (Activated Attapulgite) at tipsmotivasihidup.blogspot.de
- ↑ NEW DIATABS at medifarma.biz
- ^ Arieh Singer, Emilio Galan: Developments in Palygorskite-sepiolite Research: A New Outlook on These Nanomaterials Elsevier, Oxford 2011, ISBN 978-0-444-53607-5 , p. 306. Restricted preview in the Google book search