General name for any potassium-containing mineral, most often applied to potassium carbonate (K2CO3) or potassium hydroxide (KOH). Potassium carbonate, originally made by roasting plants to ashes in earthenware pots, is commercially produced from the mineral sylvite (potassium chloride, KCl) and is used mainly in making artificial fertilizers, glass, and soap.
The potassium content of soils and fertilizers is also commonly expressed as potash, although in this case it usually refers to potassium oxide (K2O).
A potassium compound often used in agriculture and industry; SYN. caustic potash, potassium hydroxide.