W Hat Is Hexagonal Boron Nitride available? Hexagonal Boron NItride Inorganic compounds include (h-BN), also known to be ‘black jewel’. It is usually a grayish-black powder with the chemical formula of B4C. Hexagonal Boron Nitride (second only to cubic-phase Boron Nitride and diamond) is one the hardest materials known. It is used for bullet armor,…