Epsomite

• Epsom Salt

Epsomite, known for its taste as Epsom salt or by its chemical symbol of magnesium sulfate heptahydrate, is a commonly occurring mineral from the mineral class of " sulfates ( and Related ) ". It crystallizes in the orthorhombic crystal system with the chemical composition Mg [ SO4 ] • 7H2O and usually develops granular or fibrous aggregates and crusts, rarely acicular to prismatic crystals of white color with a tinge of yellowish, greenish or pink. Even colorless epsomite is known.

Epsomite forms with Goslarit and Morenosit each a complete solid solution series.

Etymology and history

Named epsomite 1824 after his first locality, the English town of Epsom. Known and described for the first time but it was in 1806 as a deposit in connection with the present in Epsom mineral water.

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the epsomite to the mineral class of " sulfates, selenates, tellurates, chromates, molybdates, tungstates " and then to the department which was part of " water -containing sulfates without foreign anions ", where he served as named the " Epsomitgruppe " with the system no. Formed VI/C.07 and the other members Goslarit, Meridianit and Morenosit.

The 9th edition used since 2001 and valid by the International Mineralogical Association (IMA ) of the Strunz'schen Mineral classification assigns the epsomite also in the class of " sulfates ( selenates, tellurates, chromates, molybdates and tungstates ) " and then in the Department of " Sulfate ( selenates, etc. ) without additional anions, with H2O" one. This division, however, is further divided according to the 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 named as the " Epsomitgruppe " with the system no. Forms 7.CB.40 and the other members Goslarit and Morenosit.

The mainly common in English-speaking classification of minerals according to Dana assigns the epsomite in the class of " sulfates, chromates and molybdates ," there but in the department of " water -containing acids and sulfates ." Here it is also named the " Epsomitgruppe " with the system no. Find 29.06.11 and the other members Goslarit and Morenosit within the sub-division of " water -containing acids and sulfates with AXO4 × x (H2O) ".

Education and Locations

As a secondary mineral formed by oxidation of iron sulfides epsomite. But also forms by precipitation in salt lakes. It is accompanied, among other minerals of halite (rock salt ).

Locations include the fumaroles at Vesuvius in Italy, and Bisbee / Arizona, Nevada and Mount Kruger / Washington in the United States. The spectral signature of epsomite, however, was even detected on Jupiter 's moon Europa.

Similar naturally occurring magnesium sulfates are Kieserit, Pentahydrit and hexahydrite. This is about the respective mono -, penta- or hexahydrates.

Crystal structure

Epsomite crystallizes in the orthorhombic space group P212121 ( Raumgruppen-Nr. 19) with the lattice parameters a = 11.88 Å; b = 12.00 Å and c = 6.86 Å and four formula units per unit cell.

Use

In Medicine

Epsomite can as well as other water-soluble sulfates ( mirabilite, Kieserit ) are used as a purgative ( laxative ).

Precautions

Epsomite is similar to mirabilite, not stable. It can deliver under dry conditions water. If too much moisture melt Epsomitkristalle.