A naturally occurring combination of sodium carbonate and sodium bicarbonate. Natron occurred in great quantities in antiquity on the banks of several ancient lakes, mainly those of the Wadi Natrun, but was also found elsewhere. Natron was mainly used for purification purposes, both in daily life and in the religious sphere. Numerous rituals are known in which natron played an important role, including mummification. It was also used to make incense, glass and glazes.