Potash vs. Polyhalite — What's the Difference?

Potash () includes various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, which refers to plant ashes or wood ash soaked in water in a pot, which was the primary means of manufacturing the product before the Industrial Era.

Polyhalite is an evaporite mineral, a hydrated sulfate of potassium, calcium and magnesium with formula: K2Ca2Mg(SO4)4·2H2O. Polyhalite crystallizes in the triclinic system, although crystals are very rare. The normal habit is massive to fibrous.

An alkaline potassium compound, especially potassium carbonate or hydroxide.

(mineral) A mineral usually occurring in fibrous masses, of a brick-red color, being tinged with iron, and consisting chiefly of the sulphates of lime, magnesia, and soda.

See potassium carbonate.

A mineral usually occurring in fibrous masses, of a brick-red color, being tinged with iron, and consisting chiefly of the sulphates of lime, magnesia, and soda.

See potassium hydroxide.

Any of several compounds containing potassium, especially soluble compounds such as potassium oxide, potassium chloride, and various potassium sulfates, used chiefly in fertilizers.

The water-soluble part of the ash formed by burning plant material; used for making soap and glass and as a fertilizer.

(chemistry) An impure form of potassium carbonate (K₂CO₃) mixed with other potassium salts.

. Chiefly used in the names of compounds of the form "... of potash".

A class of potassium minerals, of similar applicability to potassium carbonate, such as being a fertilizer. (ie. potassium chloride, potassium hydroxide)

To treat with potassium.

The hydroxide of potassium hydrate, a hard white brittle substance, KOH, having strong caustic and alkaline properties; - hence called also caustic potash.

A potassium compound often used in agriculture and industry