Most potash is produced by refining raw potash mined or harvested throughout the world. The potash from some mines is so pure that it does not require refining at all, and it is simply pulverized and shipped to fertilizer companies and other customers.
Rarely, potash is not present as a solid mineral but as a salty brine in subterranean water deposits. All forms of potash are ionic salts and dissolve readily in water. Potash harvested from these sources is pumped to the surface and evaporated. Manufacturers then grind the highly pure evaporated potash into powder and ship it to customers.
The name potash derives not from potassium, but from the way ancient people produced this fertilizer. They would soak wood ashes in water and then evaporate the resulting liquid in a large pot over a fire. The solid that remained after all the liquid was boiled off was a crude mixture that contained potassium carbonate, one of the number of chemicals known as potash.
Most modern potash is not produced in the ancient way, as it is labor and resource intensive and produces only small amounts of potash. Nearly all modern potash comes from mineral deposits that were created when much of the earth's surface was coated with shallow oceans. When the ocean-dwelling creatures died, the potassium rich compounds in their bodies dissolved into the water and settled to the ocean floor, eventually forming the world's potash deposits.