sylvite

Sylvite is a mineral species with the chemical formula KCl, widely known as a potassium chloride mineral. It belongs to the halide mineral group and crystallizes in the cubic (isometric) system, typically forming euhedral to blocky crystals or, more commonly, granular masses. The mineral is usually colorless or white, but impurities can produce pink, red, yellow, or brown hues. It has a vitreous luster and a relatively low hardness.

Natural occurrence and associations: Sylvite forms in sedimentary evaporite deposits where magnesium and sodium chlorides dominate, often in late-stage brines. It is commonly found with halite (NaCl) and other evaporite minerals such as carnallite and polyhalite. Sylvite crystals are notable for their high potassium content, which distinguishes them from other chloride minerals.

Economic significance: The principal use of sylvite is as a source of potassium for the production of potash fertilizers. It is processed to produce potash chloride (KCl), a widely used fertilizer component, and is often recovered as part of potash ore from evaporite sequences. Globally, major potash-producing regions include parts of Canada (notably Saskatchewan), Belarus, Russia, Germany, and various salt-bearing areas in the United States.

Occurrence sites: Sylvite is mined in locations associated with large evaporite basins and salt beds. It commonly occurs in association with halite and other evaporite minerals, and commercial mining typically targets ore-rich zones where potassium chloride concentrates are economically extractable.

See also: Potash, potash fertilizer, evaporite minerals.