Potassium chloride (KCl, or potassium salt) is a metal halide salt composed of potassium and chlorine. It is odorless and has a white or colorless vitreous crystal appearance. The solid dissolves readily in water, and its solutions have a salt-like taste. Potassium chloride can be obtained from ancient dried lake deposits.[7] KCl is used as a fertilizer, [8] in medicine, in scientific applications, domestic water softeners (as a substitute for sodium chloride salt), and in food processing, where it may be known as E number additive E508. It occurs naturally as the mineral sylvite, which is named after salt's historical designations sal degistivum Sylvii and sal febrifugum Sylvii, [9] and in combination with sodium chloride as sylvinite.