The alkaline metal of silver-white colour. In air, the surface of potassium tarnishes quickly, subjected to oxidation under the influence of moisture and oxygen.
During long storage in a small air access, potassium metal covered with a layer of peroxide compounds, the existence of which presents a serious risk when attempting to cut large pieces of metal that could cause a fire or explosion.
Working with metallic potassium requires appropriate staff and special conditions.
To avoid oxidation, the technical potassium, commercially available, typically stored in a tightly closed container under a layer of mineral oil or some light hydrocarbons.
The metal of higher purity, intended for demanding purposes, stored in sealed ampoules made of a special glass.
You can buy pure potassium metal, vacuum packed in glass ampoules* at a price from 0,7 to 5 dollars per gram.
*The shape and volume of ampoules agreed with the customer.