Lake Magadi is located in the Great Rift Valley, in southern Kenya, in a vast depression whose bed is made almost entirely of solid or semisolid soda. This saline, alkaline lake of approximately 100 square kilometers in size, is composed of a dense sodium carbonate brine which precipitates vast quantities of the mineral trona (sodium sesquicarbonate), the raw material for soda ash or simply sodium carbonate. In places, the salt is up to 40 meters thick. This trona is collected and purified by the Magadi Soda Company and the resulting soda ash is sold for a variety of uses including glass manufacturing, fabric dyeing and paper production. Lake Magadi is among the few places in the world where trona forms naturally, and is the largest source of natural soda ash in Africa.

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