Kieserite, or magnesium sulfate monohydrate, is a hydrous

magnesium sulfate Magnesium sulfate or magnesium sulphate (in English-speaking countries other than the US) is a chemical compound, a salt with the formula , consisting of magnesium cations (20.19% by mass) and sulfate anions . It is a white crystalline solid, s ...

mineral with formula (MgSO₄·H₂O). It has a vitreous luster and it is colorless, grayish-white or yellowish. Its hardness is 3.5 and crystallizes in the monoclinic crystal system.

Gunningite Gunningite is one of the minerals in the Kieserite group, with the chemical formula . Its name honours Henry Cecil Gunning (1901–1991) of the Geological Survey of Canada and a professor at the University of British Columbia. Occurrence Gunningi ...

is the zinc member of the kieserite group of minerals.

Etymology

It is named after

Dietrich Georg von Kieser Dietrich Georg von Kieser (24 August 1779 – 11 October 1862) was a German physician born in Harburg. He studied medicine at the Universities of Würzburg and Göttingen, receiving his doctorate from the latter institution in 1804. For most of h ...

(Jena, Germany 1862)

Occurrence

Kieserite commonly occurs in marine

evaporite An evaporite () is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocean ...

s and rarely in volcanic environments as a sublimate. It occurs in association with halite, carnallite, polyhalite,

anhydrite Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the ...

boracite Boracite is a magnesium borate mineral with formula: Mg3 B7 O13 Cl. It occurs as blue green, colorless, gray, yellow to white crystals in the orthorhombic - pyramidal crystal system. Boracite also shows pseudo-isometric cubical and octahedral for ...

, sulfoborite,

leonite Leonite is a hydrated double sulfate of magnesium and potassium. It has the formula K2SO4·MgSO4·4H2O. The mineral was named after Leo Strippelmann, who was director of the salt works at Westeregeln in Germany. The mineral is part of the blodi ...

epsomite Epsomite, Epsom salt, or magnesium sulfate heptahydrate, is a hydrous magnesium sulfate mineral with formula MgSO4·7H2O. Epsomite crystallizes in the orthorhombic system as rarely found acicular or fibrous crystals, the normal form is as massiv ...

and celestine.

Mars

In early 2005, Mars Express, a European Space Agency orbiter, discovered evidence of kieserite in patches of

Valles Marineris Valles Marineris (; Latin for '' Mariner Valleys'', named after the ''Mariner 9'' Mars orbiter of 1971–72 which discovered it) is a system of canyons that runs along the Martian surface east of the Tharsis region. At more than long, wide and ...

(the largest canyon on Mars), along with

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywa ...

and polyhydrated

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...

s. This is direct evidence of Mars's watery past and augments similar discoveries made by the

Mars Exploration Rover NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, '' Spirit'' and '' Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rovers to explore the Martian surface ...

Opportunity in 2004.

Moons of Jupiter

Kieserite might also be a rock-forming mineral in the icy mantle of the outer three

Galilean moons The Galilean moons (), or Galilean satellites, are the four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto. They were first seen by Galileo Galilei in December 1609 or January 1610, and recognized by him as satellites of Jupite ...

(

Europa Europa may refer to: Places * Europe * Europa (Roman province), a province within the Diocese of Thrace * Europa (Seville Metro), Seville, Spain; a station on the Seville Metro * Europa City, Paris, France; a planned development * Europa Clif ...

, Ganymede,

Callisto Callisto most commonly refers to: * Callisto (mythology), a nymph *Callisto (moon), a moon of Jupiter Callisto may also refer to: Art and entertainment *''Callisto series'', a sequence of novels by Lin Carter *''Callisto'', a novel by Torsten Kr ...

). At pressures higher than 2.7

GPa Grading in education is the process of applying standardized measurements for varying levels of achievements in a course. Grades can be assigned as letters (usually A through F), as a range (for example, 1 to 6), as a percentage, or as a numbe ...

, kieserite transforms to a triclinic crystal structure.

Uses

It is used in the production of

Epsom salt Epsomite, Epsom salt, or magnesium sulfate heptahydrate, is a hydrous magnesium sulfate mineral with formula MgSO4·7H2O. Epsomite crystallizes in the orthorhombic system as rarely found acicular or fibrous crystals, the normal form is as massiv ...

and as a fertilizer, the overall global annual usage in agriculture in the mid 1970s was 2.3 million tons. Kieserite crystal structure

Kieserite is also used for cleaning hard water deposits from tiles, stones, and other pool and fountain lining materials. Due to its hardness, which is greater than hard water deposits but less than tiles and other water feature linings, it is blasted at the hard water deposits to remove them.

When to use kieserite as a fertilizer

Response to Kieserite is likely where: • Soil Mg levels are low • pH is high • Intensive liming occurs to raise the pH • Nitrogen is applied as ammonium, as this can lead to an antagonism between ammonium and magnesium • Compacted soils exist • There is a period of wet/cold weather • Dry weather occurs leading to low magnesium mobility in the soil profile.

References

{{Reflist Magnesium minerals Sulfate minerals Monoclinic minerals Minerals in space group 15 Evaporite