Boron


Boron compounds may have been known for about 6000 years, starting with the Babylonians. The Egyptians, Chinese, Tibetans and Arabians are reported to have used such materials. The Arabs used the expression baurach for a number of minerals including the now familiar borax.

Elemental boron was not known until the early nineteenth century when Sir Humphrey Davy, Gay-Lussac and Thenard prepared boron by reduction of boron trioxide with potassium and by electrolysis of moistened boric acid. The purity of their products was about 50%.

Fifty years later impure boron products resembling both diamond and graphite were produced. The diamond-hard material was found to be largely aluminum boride (AlB12), while the graphite variety was a complex boron-aluminum-carbon. Much later, a higher purity boron was made by reduction of boron trioxide with magnesium. Purities of about 90% can be achieved by this procedure. The product is light boron in color and is considered to be amorphous.

Boron did not become of interest until the twentieth century when it was found that it formed many unusual and complex compounds. It has been during the last forty years that the right physical and chemical properties have been determined. High purity boron produced by electrolysis and vapor deposition methods have made such determinations possible.