Sodium tetraborate, borax - sodium salt of boric acid. Approved in the European Union for use in food as a preservative (E285).
general information
Borax is one of the main minerals of boric ores. Chemical formula : Already 2 B 4 O 7. Most often exists as a crystalline hydrate of the composition Na 2 B 4 O 7 ·10H 2 O. Syngonia monoclinic. White color, Gray, green. Fragile. Hardness 2-2,5. Density 1,7. Crystals are short prismatic, sometimes tabular. Glitter glass, to resin. The dash is white. Translucent (to opaque). Diamagnetic. Dissolves in water.
Lies together with halite, boronatrocalcite, thenardite, plaster etc. A typical evaporite mineral is formed by the evaporation of salt lakes. Large deposits are located in the USA, smaller ones in India, China, Iran. In particular, found on the shores of lakes in Kashmir, Tibet, California and the Taman Peninsula. You can sodium tetraborate buy in "Areolab" companies.
Application:
- to get boron,
- when soldering as a flux in jewelry,
- in the manufacture of optical glass, enamels, etc..