In the late 1980s, the only mineral exploited in Chad was sodium carbonate, or natron. Also called sal soda or washing soda, natron was used as a salt for medicinal purposes, as a preservative for hides, and as an ingredient in the traditional manufacture of soap; herders also fed it to their animals. Natron deposits were located around the shore of Lake Chad and the wadis of Kanem Prefecture, and near the oasis of Faya-Largeau.