Aluminium Borides

Two borides are known, AlB₂ and AlB₁₂, and crystals have also been prepared containing boron, aluminium, and carbon. All the substances were prepared originally by Wohler and Deville, and regarded as allotropic forms of boron crystallising out from solution in molten aluminium. Subsequently they recognised that their graphitic boron was a boride of aluminium AlB₂, but looked upon the aluminium and carbon in their adamantine boron as accidental impurities.