Natron is a hydrated sodium carbonate mineral with the formula Na2(CO3)·10(H2O). In color it is white to colorless when pure, varying to gray or yellow with impurities. It has a specific gravity of 1.42 to 1.47 and a Mohs hardness of 1. It crystallizes in the monoclinic crystal system typically forming efflorescences and encrustations. Natron can be found in saline lake beds in arid environments. It effloresces (loses water) in dry air and is transformed into the monohydrate thermonatrite (Na2(CO3)·(H2O)). It occurs in association with thermonatrite, trona, mirabilite, gaylussite, gypsum and calcite.
The English word natron is a French cognate derived from the Spanish natrón, via Arabic natrun, and from the Greek nitron.
Use in Antiquity
One common use was in ancient Egypt as a part of mummification. The mineral works as a drying agent, drawing the water out of the body. At the same time the bicarbonate, when subjected to moisture, increases the pH and creates a hostile environment for bacteria. Natron was also thought to promote spiritual safety for both the living and the dead. It was also added to castor oil to produce a smokeless fuel which allowed Egyptian artisans to paint elaborate artworks inside ancient tombs without them becoming besmirched with soot. Natron has also been known to be used as a cleansing product for the home as well as the body which includes the teeth and was used as an early mouthwash. It has also been linked to early antiseptics if placed on wounds and minor cuts. It was also used to rid a house of vermin. Natron is also an ingredient in the making of the distinct color "Egyptian blue". Natron was used to make ceramics and glass as well as to solder precious metals together. If natron was mixed with salt, it could be used to preserve fish and meat. It could also be mixed with oil and it became an early form of soap. Natron was commonly used in glass-making, by the Romans and others, until trade declined after 640 AD.
Prior to baking, Bavarian pretzels are dipped into "Natronlauge". Although this German term literally translates into "natron-lye", it refers to sodiumhydroxide (NaOH) solution.