Kieserite

• Martensite

Kieserit is a rarely occurring mineral from the mineral class of " sulfates ( and Related, see classification) ". It crystallizes in the monoclinic crystal system with the composition Mg [ SO4 ] · H2O, that is chemically a hydrous magnesium sulfate.

Kieserit rarely developed dipyramidal larger crystals. He usually can be found in the form of coarse to fine-grained or mass Riger mineral aggregates. In pure form, the mineral is colorless and transparent. Through multiple refraction due to lattice defects or polycrystalline training but it can also appear white and accept by foreign admixtures a light gray or light yellow color, the transparency decreases accordingly.

Special Features

In humid air, Kieserit absorbs water and converts to epsomite. His own crystal water is the mineral only on heating above 200 ° C onto.

In water Kieserit is only slowly soluble, as a powder and mixed with water it hardens similar to plaster.

Etymology and history

Kieserit was first discovered in Staßfurt in Saxony-Anhalt and described in 1861 by Eduard Reichardt, who named the mineral after Dietrich Georg Kieser ( 1779-1862 ). This was a professor, physician and psychiatrist at the University of Jena.

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the Kieserit belonged mineral class of " sulfates, chromates, molybdates, tungstates " and then to the Department of " water -containing sulfates, without foreign anions ", where he was named after him " Kieserit group "with the system no. Formed VI/C.01 and the other members Cobaltkieserit, Dwornikit, Gunningit, Poitevinit, Sanderit, Szmikit and Szomolnokit.

The 9th edition valid since 2001 and of the International Mineralogical Association (IMA ) used the Strunz'schen Mineral classification assigns the Kieserit in the extended class of " sulfates ( selenates, tellurates, chromates, molybdates and tungstates ) ," there but also in the department of a " without other anions, with H2O Sulfate ( selenates, etc.) ". However, this is further divided according to the relative size of the cations involved, so that the mineral is "With only medium-sized cations " to find according to its composition in the subdivision where it is also named after him " Kieserit group " with the System No.. 7.CB.05 forms.

The mostly commonly used in English-speaking classification of minerals according to Dana assigns the Kieserit in the class of " sulfates, chromates and molybdates " and there in the department of " water -containing acids and sulfates " one. He is also in the " Kieserit group ( Monohydrate ) " with the system no. 29/06/02 found within the sub-division " Water-containing acids and sulfates with AXO4 × x (H2O) ".

Education and Locations

Kieserit found in marine salt deposits and forms especially in the overburden of the salt rock salt Staßfurter work benches up to 30cm thickness. Furthermore Kieserit part of kieseritischem hard salt. In rare cases, Kieserit also forms by deposition from volcanic gases. Accompanying minerals occur among others anhydrite, Boracite, carnallite, Celestine, epsomite, halite, Leonit, polyhalite and Sulfoborit.

A rare mineral formation Kieserit could be proven so far only in a few localities, where so far (as of 2012) are about 60 localities known as. Apart from its type locality Staßfurt the mineral occurred in Germany, among others, still in Neuhof ( near Fulda ), Wintershall and potash Hattorf at Philippstal in Hesse; at Wath, Taught and Diekholzen in Lower Saxony; at Tarthun and Westeregeln in Saxony -Anhalt and in Bleicherode, Ronneburg and flag in Thuringia.

In Austria, Kieserit found so far at Dürr mountain in Salzburg and in the salt mines at Altausee in Styria and Hallstatt in Upper Austria.

Other localities lie in Australia, among others, at Mount Isa; in the English county of North Yorkshire; the Greek community Lavrio; on Surtsey in Iceland; Monte Sambuco in the Italian province of Caltanissetta, in Kings County ( New Brunswick) Canada; in the Kazakh Aktobe regions ( Aksaital ) and western Kazakhstan; in 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; in Kladno (Bohemia ) and Zastávka ( Moravia ) in the Czech Republic; in Ukraine, at Pécs - Vasas ( Pecs Eisenau ) in the Hungarian Baranya county, and in several states of the United States of America.

Crystal structure

Kieserit crystallizes in the monoclinic space group C2 / c ( Raumgruppen-Nr. 15) with the lattice parameters a = 6.89 Å; b = 7.62 Å; c = 7.65 Å and 117.7 ° and β = 4 formula units per unit cell.

Use

Kieserit serves as raw material for the production of fertilizers ( see Kieserit ( fertilizer ) )

In medicine Kieserit serves as well as other water-soluble sulfates (eg: mirabilite ) as a laxative ( laxative ).