Sylvinite

 Sylviniteis asedimentary rockmade of a mechanical mixture of the mineralssylvite(KCl, or potassium chloride) andhalite(NaCl, orsodium chloride).Sylvinite is the most important source for the production ofpotashinNorth America, Russia and the UK.MostCanadianoperations mine sylvinite with proportions of about 31% KCl and 66% NaCl with the balance being insoluble clays,anhydriteand in some locationscarnallite. Other deposits of sylvinite are in Belarus, Brazil, France, Germany, Kazakhstan, Slovakia and Spain.

Sylvinite from Perm Krai, Russia

Close-up view of sylvinite from Perm, Russia

This article uses material from the Wikipedia article  Metasyntactic variable, which is released under the  Creative Commons Attribution-ShareAlike 3.0 Unported License.