Natron

Natron is a carbonate mineral with the formula Na2CO3·10H2O. Wikipedia's illustration shows natron deposits in the Era Kohor crater in the Tibesti Mountains of Chad. It is colourless to white, greyish or yellowish, and colourless in transmitted light. The article says natron was used during mummification ceremonies in ancient Egypt because it absorbs water and behaves as a drying agent, and that its carbonate raises alkalinity, which makes a hostile environment for bacteria. It adds that in some cultures natron was thought to enhance spiritual safety for both the living and the dead. The Pyramid Texts describe natron pellets used as funerary offerings and in purification rites, with natron from both Lower and Upper Egypt. The article carries a notice that it needs more citations, and one sentence in it is marked as needing a citation.