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Kieseriet (Kieserite).jpg
Category Sulfate minerals
(repeating unit)
Strunz classification 07.CB.05
Dana classification
Crystal symmetry 2/m
Color Colorless, grayish-white or yellowish
Crystal habit Massive, granular
Crystal system Monoclinic
Cleavage {110} and {111} perfect
Fracture Uneven
Tenacity Fragile
Mohs scale hardness 3.5
Luster Vitreous to dull
Streak White
Diaphaneity Transparent to translucent
Specific gravity 2.57
Optical properties Biaxial (+)
Refractive index nα = 1.520 nβ = 1.533 nγ = 1.584
References [1][2]

Kieserite is the magnesium sulfate mineral (MgSO4·H2O) and is named after Dietrich Georg von Kieser (Jena, Germany 1862). It has a vitreous luster and it is colorless, grayish-white or yellowish. Its hardness is 3.5 and it has a monoclinic crystal system. It is used in the production of Epsom salt and as a fertiliser, the overall global annual usage in agriculture in the mid 1970s was 2.3 million tons.[3]

In early 2005, Mars Express, a European Space Agency orbiter, discovered evidence of kieserite in patches of Valles Marineris (the largest canyon on Mars), along with gypsum and polyhydrated sulfates. This is direct evidence of Mars's watery past and augments similar discoveries made by the Mars Exploration Rover Opportunity in 2004.

Crystal structure of kieserite

Related minerals[edit]

See also[edit]


  1. ^ Webmineral data
  2. ^ Mindat
  3. ^ Industrial Inorganic Chemistry, Karl Heinz Büchel, Hans-Heinrich Moretto, Dietmar Werner, John Wiley & Sons, 2d edition, 2000, ISBN 9783527613335