Sylvite, or sylvine, is potassium chloride
(KCl) in natural mineral
form. It forms crystals in the isometric
system very similar to normal rock salt, halite
Cl). The two are, in fact, isomorphous. Sylvite is colorless to white with shades of yellow and red due to inclusions. It has a Mohs hardness
of 2.5 and a specific gravity
of 1.99. It has a refractive index of 1.4903. Sylvite has a salty taste with a distinct bitterness.
Sylvite is one of the last evaporite
minerals to precipitate out of solution. As such, it is only found in very dry saline areas. Its principal use is as a potassium fertilizer.
left|180px|Sylvite from Germany
Sylvite is found in many evaporite deposits worldwide. Massive bedded deposits occur in New Mexico and western Texas, and in Utah in the US, but the largest world source is in Saskatchewan, Canada. The vast deposits in Saskatchewan
, Canada were formed by the evaporation of a Devonian
seaway. Sylvite is the official mineral of Saskatchewan.
Sylvite was first described in 1832 at Mount Vesuvius
and named for the Dutch chemist
, François Sylvius de le Boe
Sylvite, along with quartz, fluorite and halite, is used for spectroscopic prisms and lenses.]
Mineral Resources of Saskatchewan
Category:Minerals in space group 225