Kieserite (mineral)

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Kieserite
Kieseriet (Kieserite) .jpg
General and classification
other names

Martinsite

chemical formula Mg [SO 4 ] • H 2 O
Mineral class
(and possibly department) 		Sulfates (and relatives)
System no. to Strunz
and to Dana 		7.CB.05 ( 8th edition : VI / C.01)
06/29/02/01
Crystallographic Data
Crystal system monoclinic
Crystal class ; symbol monoclinic prismatic; 2 / m
Space group C 2 / c (No. 15)Template: room group / 15
Lattice parameters a  = 6.89  Å ; b  = 7.62 Å; c  = 7.65 Å
β  = 117.7 °
Formula units Z  = 4
Physical Properties
Mohs hardness 3.5
Density (g / cm 3 ) measured: 2.571; calculated: 2.571
Cleavage completely according to {110} and {111}; imperfect after { 1 11}, { 1 01} and {011}
Break ; Tenacity uneven
colour colorless, white, light gray, light yellow
Line color White
transparency transparent to translucent
shine Glass gloss to matt
Crystal optics
Refractive indices n α  = 1.520
n β  = 1.533
n γ  = 1.584
Birefringence δ = 0.064
Optical character biaxial positive
Axis angle 2V = 55 ° (measured); 56 ° (calculated)
Other properties
Chemical behavior water soluble, bitter taste

Kieserite is a rarely occurring mineral from the mineral class of the " sulfates (and relatives, see classification )". It crystallizes in the monoclinic crystal system with the composition Mg [SO 4 ] · H 2 O, so it is chemically a water-containing magnesium sulfate .

Kieserite rarely develops larger dipyramidal crystals . It is mostly found in the form of coarse to fine-grained or massive or coarse mineral aggregates . In its pure form, the mineral is colorless and transparent. However, due to multiple light refraction due to lattice construction defects or polycrystalline formation, it can also appear white and, due to foreign admixtures, take on a light gray or light yellow color, the transparency decreasing accordingly.

Etymology and history

Kieserite was first discovered near Staßfurt in Saxony-Anhalt and described in 1861 by Eduard Reichardt , who named the mineral after Dietrich Georg von Kieser (1779–1862). He was a professor, doctor and psychiatrist at the University of Jena .

A mixture of 9.02% anhydrous Epsom salt (= magnesium sulfate , MgSO 4 ) and 90.98% table salt from Staßfurt was named Martinsit by Carl Karsten in 1845 .

classification

In the now outdated, but still in use 8th edition of the mineral classification according to Strunz , the kieserite mineral class belonged to the "sulfates, chromates, molybdates, wolframates" and there to the department of "hydrous sulfates, without foreign anions ", where he named the " Kieserit Group "with the system no. VI / C.01 and the other members Cobaltkieserit , Dwornikit , Gunningit , Poitevinit , Sanderit , Szmikit and Szomolnokit 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), assigns kieserite to the extended class of "sulfates (selenates, tellurates, chromates, molybdates and wolframates)", but also to the Section of “Sulphates (selenates etc.) without additional anions, with H 2 O”. However, this is further subdivided according to the relative size of the cations involved , so that the mineral can be found according to its composition in the sub-section “With only medium-sized cations”, where the “Kieserite group” named after it with the system no . 7.CB.05 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns kieserite to the class of "sulfates, chromates and molybdates" and there in the category of "water-containing acids and sulfates". Here it is also in the "Kieserite group (monohydrate)" with the system no. 06/29/02 to be found in the subsection " Water-based acids and sulphates with AXO4 × x (H2O) ".

Crystal structure

Kieserite crystallizes monoclinically in the space group C 2 / c (space group no. 15) with the lattice parameters a  = 6.89  Å ; b  = 7.62 Å; c  = 7.65 Å and β = 117.7 ° as well as 4 formula units per unit cell . Template: room group / 15

properties

Kieserite absorbs water in moist air and transforms into epsomite . The mineral only releases its own crystal water when heated to over 200 ° C.

Kieserite is only slowly soluble in water; as a powder and mixed with a little water, it hardens like plaster of paris .

Education and Locations

Kieserit found in marine salt - deposits , making especially in overburden salt of the Stassfurt rock salt work benches up to 30 cm thick. Kieserite is also a component of kieseritic hard salt . In rare cases, kieserite is also formed by separation from volcanic gases . The accompanying minerals include anhydrite , boracite , carnallite , celestine , epsomite , halite , leonite , polyhalite and sulfoborite .

As a rare mineral formation, kieserite has only been found at a few sites so far, with around 60 sites being known to date (as of 2012). In addition to its type locality in Staßfurt, the mineral appeared in Germany at Neuhof (near Fulda) , Wintershall and in the Hattorf potash plant near Philippsthal in Hesse; at Wathlingen , Lehrte , Diekholzen and in the Siegfried-Giesen potash plant in Lower Saxony; at Tarthun and Westeregeln in Saxony-Anhalt and at Bleicherode , Ronneburg and Merkers in Thuringia.

In Austria, Kieserite has so far been found near Dürrnberg in Salzburg and in the salt mines near Altaussee in Styria and Hallstatt in Upper Austria.

Other sites are among others at Mount Isa in Australia; in the English county of North Yorkshire ; the Greek municipality of Lavrio ; on Surtsey in Iceland; on Monte Sambuco in the Caltanissetta Italian Free Community Consortium , in Kings County, New Brunswick , Canada; in the Kazakh regions of Aqtöbe (Aksaital) and Western Kazakhstan ; at Winterswijk , Veendam and Zuidwending in the Netherlands; in the Pakistani province of Punjab ; at Lasisk and Kłodawa in Poland; at Kopeisk in Russia; at Smolník in Slovakia; near Kladno (Bohemia) and Zastávka (Moravia) in the Czech Republic; in the Ukraine , near Pécs-Vasas ( Fünfkirchen-Eisenau ) in the Hungarian county of Baranya and in several states of the United States of America.

Kieserite could also be detected on Mars , more precisely in the area of ​​"Juventae Chasma" in Terra Margaritifer .

use

In medicine, like other water-soluble sulfates (e.g. mirabilite ) , kieserite is used as a laxative .

In industrial agriculture , the mineral is used as a raw material for the production of kieserite fertilizer .

See also

literature

Web links

Commons : Kieserite  - collection of images, videos and audio files

Individual evidence

  1. ↑ Webmineral - Kieserite
  2. ↑ 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 , p.  380 .
  3. ↑ a b c Kieserite . 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; 66  kB ]).
  4. ↑ a b c d e f g Mindat - Kieserite
  5. ^ Albert H. Chester: A dictionary of the names of minerals inluding their history and etymology . 1st edition. John Wiley & Sons, New York 1896, p. 168 ( available online at archive.org ).
  6. ↑ The Martinsit, a salt found in the rock salt warehouse in Stassfurth . In: Otto Linné Erdmann, Richard Felix Marchand (Ed.): Journal for practical chemistry . tape  36 . Publisher by Johann Ambrosius Barth, Leipzig 1845, p. 127 ( limited preview in Google Book search).
  7. ↑ a b Friedrich Klockmann : Klockmanns textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp.  605 (first edition: 1891).
  8. ↑ Mindat - Number of localities for Kieserite