Carnallite is an evaporite mineral, a hydrated potassium magnesium chloride with formula: KMgCl3·6(H2O). It is variably colored yellow to white, reddish, and sometimes colorless or blue. It is usually massive to fibrous with rare pseudohexagonal orthorhombic crystals. It is transparent to translucent with a greasy luster. The refractive indices are nα=1.467 nβ=1.476 nγ=1.494. It has a Mohs hardness of 2.5 and a specific gravity of 1.6. The mineral is deliquescent (absorbs moisture from the surrounding air) and specimens must be stored in an airtight container.

Carnallite occurs with a sequence of potassium and magnesium evaporite minerals sylvite, kainite, picromerite, polyhalite and kieserite. Carnallite is a somewhat rare double chloride mineral which only forms under a specific environmental conditions in an evaporating sea or sedimentary basin. It is mined for both potassium and magnesium and occurs in the evaporite deposits of Carlsbad, New Mexico; the Paradox Basin in Colorado and Utah; Stassfurt, Germany; the Perm Basin, Russia; and the Williston Basin in Saskatchewan, Canada. These deposits date from the Devonian through the Permian Periods. In contrast, both Israel and Jordan produce potash from the Dead Sea by using evaporation pans to further concentrate the brine until carnallite precipitates, dredging the carnallite from the pans, and processing to remove the magnesium chloride from the potassium chloride.

Carnallite was first described in 1856 from its type location of Stassfurt Deposit, Saxony-Anhalt, Germany. It was named for the Prussian mining engineer, Rudolph von Carnall (1804-1874).

ee also

*List of minerals
*List of minerals named after people


* [ Mindat with location data]
* [ Webmineral]
* [ Mineral galleries]

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Look at other dictionaries:

  • Carnallite — Car nal*lite, n. [G. carnallit, fr. Von Carnall, a Prussian.] (Min.) A hydrous chloride of potassium and magnesium, sometimes found associated with deposits of rock salt. [1913 Webster] …   The Collaborative International Dictionary of English

  • carnallite — ● carnallite nom féminin (de von Carnall, nom propre) Chlorure double hydraté de potassium et de magnésium, exploité industriellement comme minerai de magnésium …   Encyclopédie Universelle

  • carnallite — [kär′nəl īt΄] n. [after Rudolf von Carnall (1804 74), Ger mineralogist + ITE1] a hydrous chloride of magnesium and potassium, MgCl2·KCl·6H2O: a valuable source of potassium …   English World dictionary

  • carnallite — /kahr nl uyt /, n. Mineral. a white hydrous chloride of potassium and magnesium, KMgCl3·6H2O, used chiefly as a source of potassium and magnesium. [1875 85; named after R. von Carnall (1804 74), German mining official; see ITE1] * * * ▪ mineral… …   Universalium

  • carnallite — karnalitas statusas T sritis chemija apibrėžtis Mineralas. formulė KMgCl₃·6H₂O atitikmenys: angl. carnallite rus. карналлит …   Chemijos terminų aiškinamasis žodynas

  • carnallite — noun Etymology: German Carnallit, from Rudolf von Carnall died 1874 German mining engineer Date: 1876 a mineral consisting of hydrous potassium magnesium chloride that is an important source of potassium …   New Collegiate Dictionary

  • carnallite — noun A saline evaporite composed of a mixture of potassium chloride and magnesium chloride, with the chemical formula KMgCl·6HO …   Wiktionary

  • carnallite — car·nal·lì·te s.f. TS mineral. minerale costituito da cloruro doppio di potassio e magnesio, usato per l estrazione del potassio {{line}} {{/line}} DATA: 1881. ETIMO: der. di Carnall, nome dell ingegnere minerario tedesco Rudolf von Carnall (1804 …   Dizionario italiano

  • carnallite — {{hw}}{{carnallite}}{{/hw}}s. f. Minerale, cloruro doppio di potassio e magnesio …   Enciclopedia di italiano

  • carnallite — pl.f. carnalliti …   Dizionario dei sinonimi e contrari

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