The chemical formula of the mineral Epsomite  is indicated by MgSO4 – 7H2O or Hydrated Magnesium Sulfate. Epsomite is actually Sulfate mineral. The name of the mineral Epsomite and the Epsom salt was derived from the name of its type of locality at Epsom, England. The mineral species was first systematically described in 1806 for its occurrence near Epsom, Surrey in England. Mineral Epsomite is known to crystallize in the orthorhombic system. In optical mineralogy, this crystal system comprises crystals having three mutually perpendicular axes, of which all are of different lengths.

 

Mineral Epsomite is also considered as a source of magnesium salts. It has also various chemical and medicinal uses. The medicinal uses of the magnesium sulfate were actually first discovered from the mineral waters at Epsom, England. But most commonly, Epsomite is used as mineral specimen and it commonly exhibited interesting microscope views under geological polarizing microscopes. The identification of mineral Epsomite is usually easy. One identification factor is its solubility. Another is its taste. Epsomite and Epsom salt have bitter taste. Most collectors’ specimen has the detriment of easy solubility.

 

            Mineral Epsomite is commonly found colorless and sometimes white with pale shades of pink and green, which can be splendidly exhibited when viewed with the aid of petrographic polarizing microscopes. Epsomite mineral specimens are commonly found exhibiting a vitreous luster if in large crystals and silky to earthy luster in most specimens when closely evaluated in reflected light of the petrographic polarizing microscope. Epsomite is usually found showing perfect cleavage in one direction and distinct in two other directions and these cleavages can be seen more clearly visible when viewed under polarizing light microscope. Epsomite is commonly found exhibiting a conchoidal fracture when viewed closely with the aid of petrographic polarizing microscopes. The specific gravity measure of the mineral usually gives an approximate value of 1.7 grams per cubic centimeters, which is considered well below average. The hardness measure of the mineral when it is evaluated using the Mohs scale method is commonly found ranging from 2 to 2.5. When mineral section of the Epsomite is rubbed on a white porcelain streak plate, it is commonly found leaving a white to colorless streak.

 

When Epsomite is evaluated between crossed nicols of petrographic polarizing microscopes, it is commonly found having biaxial negative figure. The refractive index found is commonly ranging from 1.433 to 1.461 as described in the field of optical mineralogy. Epsomite also exhibits a moderate surface relief when closely evaluated under several adjustments on the aperture diaphragm of the polarizing microscopes used in optical mineralogy. The maximum birefringence of the mineral is usually 0.0280. Most crystals of Epsomite are found translucent to transparent in appearance. The crystal habit of the mineral include fibrous, stalactitic, acicular, encrusting, granular and botryoidal which are usually splendidly exhibited under petrographic polarizing microscope fro mineralogists. There are also few large Epsomite crystals that can be found. This is because Epsomite is most commonly found forming crusts and massive crystals that are usually very interesting when viewed under geological polarizing microscopes. Attractive fibrous Epsomite crystals that are almost cotton-like aggregates and exhibiting silky luster when viewed in reflected light of polarized microscopes are the best Epsomite specimens found.

 

Mineral Epsomite is very soluble in water. This fact serves as a detriment to most mineral collections as they may happen to absorb water molecules from the air and deteriorate over time. Epsomite has a bitter taste just like Epsom salt. Mineral Epsomite is not magnetic. It also has no dispersion and is not pleochroic. Mineral Epsomite is also not radioactive. It is recommended to clean the Epsomite mineral specimen gently with alcohol before keeping them in a sealed container. If exposed in dry air conditions, mineral Epsomite usually loses one molecule of water and this easily converts to the very closely related mineral called hexahydrite. One mole lost in Epsomite can lead to the existence of a new mineral because the water molecules of mineral Epsomite are very intricately involved with the structure itself. This can be seen in the symmetry transformation of the mineral from being orthorhombic Epsomite to monoclinic hexahydrite. The symmetry of the mineral Epsomite is rather very notable. This is because Epsomite mineral is only one of those few minerals having symmetry that has just three 2-folds rotational axes at right angles to each other. There are no other symmetry operations or mirror planes. But then unfortunately, mineral Epsomite does not typically form well-shaped crystals that show the unusual symmetry possessed by the mineral.

 

            Mineral Epsomite is commonly associated with other interesting minerals like aragonite, pyrite, gypsum, calcite, mirabilite and pyrrhotite. The best field indicators of mineral Epsomite include crystal habit, solubility in water, low density, associations and taste. Mineral Epsomite most commonly forms as efflorescences on cave taverns from the deposition of material from saline springs. It is only found existing in arid regions as well as in dry caves which would protect it from rain and moisture, for otherwise it will dissolve. Epsomite may also form efflorescences in tunnels of sulfide mines from the deposition of sulfur and magnesium-rich water which is created through mining operations. It can be also found in playa lakes. It can be also found forming on limestone cave walls as well as in timbers of mines. Epsomite mineral has been found in deposits from hot springs and also fumaroles like the ones on Mt. Vesuvius in Italy. Epsomite is commonly found forming large sedimentary beds that were included in some very unusual marine salt deposits in South Africa. Mineral Epsomite notably occurs at some famous mineral localities including Epsom in England, Stassfurt in Germany, El Tiro Mine, Arizona and Carlsbad, New Mexico in USA, Ashcroft in British Columbia, Canada as well as South Africa.