Natron: Properties and Occurrences

Natron is a mineral of hydrous sodium carbonate, often found crystallized with other salts. It is a naturally occurring mixture of sodium carbonate decahydrate (Na2CO3·10H2O, a kind of soda ash) and around 17% sodium bicarbonate (also called baking soda, NaHCO3) along with small quantities of sodium chloride and sodium sulfate. The name ‘natron’ is commonly used for the natural mixture of salts obtained from dry lake beds and mineral deposits. It is a natural compound of sodium salts, was a very important product in ancient history.

Natron is white to colorless when pure, varying to gray or yellow with impurities. It can act as a desiccant and was used in mummification. In modern mineralogy, the term natron has come to mean only the sodium carbonate decahydrate (hydrated soda ash) that makes up most of the historical salt.

General information

  • Formula: Na2CO3·10H2O
  • Color: Colorless to white, grayish, yellowish; colorless in transmitted light.
  • Specific Gravity: 1.478
  • Crystal System: Monoclinic
  • Streak: white

Natron – a Colorless to white, grayish, yellowish crystal

Properties

Natron is the mineralogical name for the compound sodium carbonate decahydrate, which is the main component in historical natron. Sodium carbonate decahydrate has a specific gravity of 1.42 to 1.47 and a Mohs hardness of 1. It crystallizes in the monoclinic-domestic crystal system, typically forming efflorescences and encrustations.

  • Lustre: Vitreous
  • Transparency: Transparent, Translucent
  • Hardness: 1 – 1½ on Mohs scale
  • Tenacity: Brittle
  • Cleavage: Distinct/Good On {001} distinct; on {010} imperfect; on {110} in traces.
  • Fracture: Conchoidal
  • Density: 1.478 g/cm3 (Measured)   

The term hydrated sodium carbonate is commonly used to encompass the monohydrate, the decahydrate, and the heptahydrate, but is often used in industry to refer to the decahydrate only.

Occurrences

Natron deposits are sometimes found in saline lake beds that arose in arid environments. Throughout history, natron has had many practical applications that continue today in the wide range of modern uses of its constituent mineral components. It was produced in Egypt, Middle East, and Greece.

Uses

In ancient Egypt, natron was used for making Incense, manufacturing Glass, bleaching Linen, and as a Preservative in the mummification process. It was used for medicine, cookery, agriculture, glass-making, and to dehydrate Egyptian mummies.

Information Source: