Also found in: Dictionary, Wikipedia.


MgSO4·7H2O A mineral that occurs in clear, needlelike, orthorhombic crystals; commonly, it is massive or fibrous; luster varies from vitreous to milky, hardness is 2-2.5 on Mohs scale, and specific gravity is 1.68; it has a salty bitter taste and is soluble in water. Also known as epsom salt.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



(Epsom salt), a mineral of the sulfate class having the molecular formula MgS04-7H20. Epsomite crystallizes in the orthorhombic system, with prismatic or acicular crystals. White or colorless, it has a glassy luster. Epsomite has a hardness of 2 to 2.5 on Mohs’ scale, and it has a density of 1,680 kg/m3. The mineral is soluble in water and has a bitter, salty taste. It is formed by the evaporation of brine from sulfate salt lakes with a high magnesium content. Epsomite has various uses (seeMAGNESIUMSULFATE).

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The shift towards the S[O.sub.4] corner showed by other samples is due to the dissolution of more soluble sulfates as epsomite (P1) and [Na.sub.2]S[O.sub.4]-bearing salts (P2, P3).
Using current technology on ground-based telescopes, Brown and Hand have identified a spectroscopic feature on Europa's surface that indicates the presence of a magnesium sulfate salt, a mineral called epsomite, that could only originate from the ocean below.
After a few days some crystals had indeed appeared, but they were obviously not orthorhombic epsomite (Mg[SO.sub.4]-7[H.sub.2]O).
Figure 4 shows specimens of deteriorated epsomite that probably should have been removed long ago.
White epsomite fibers occur on melanterite and chalcanthite stalactites.
Admixtures of alunogen and epsomite are reported, with no details (Eckel, 1997).
Associated minerals are: coskrenite-(Ce), zugshunstite-(Ce), melanterite, halotrichite, pickeringite, apjohnite, epsomite and other hydrated sulfates.
Associated minerals are: epsomite, members of the "hair salt" family (the most abundant of which is apjohnite), gypsum, jarosite, tschermigite, diadochite and four other new species: levinsonite-(Y), zugshunstite-(Ce), the probable ammonium analogue of slavikite and an iron phosphate.
A relatively rare secondary mineral, botryogen occurs as thin, orange-yellow crusts up to several square centimeters in area in the Andrassy III section, associated with epsomite, melanterite and copiapite (Szakall et al., 1997).
Species confirmed by X-ray diffraction during this study include alstonite, anglesite, ankerite, aragonite, barytocalcite, barite, brochantite, epsomite, harmotome, hydromagnesite, jarosite, marcasite, melanterite, millerite, serpierite, siderite, sulfur and witherite.
Alum Cave Bluff, a Dana locality for apjohnite, epsomite, melanterite and potash alum, has yielded good microcrystals of several rare sulfate minerals, including three new rare-earth sulfates, and is the first North American occurrence of slavikite.
Epsomite was found by the writer as densely packed acicular crystals up to 5 mm in length coating shales in the Victory mines.