or ▁industry ▁is ▁produced ▁by ▁the ▁decomposition ▁of ▁di bor ane ▁at ▁high ▁temper atures ▁and ▁then ▁further ▁pur ified ▁by ▁the ▁zone ▁mel ting ▁or ▁C zo ch ral ski ▁processes . ▁ ▁The ▁production ▁of ▁bor on ▁comp ounds ▁does ▁not ▁involve ▁the ▁formation ▁of ▁element al ▁bor on , ▁but ▁explo its ▁the ▁convenient ▁avail ability ▁of ▁bor ates . ▁ ▁Character istics ▁ ▁All otrop es ▁ ▁Bor on ▁is ▁similar ▁to ▁carbon ▁in ▁its ▁cap ability ▁to ▁form ▁stable ▁c oval ently ▁bond ed ▁mole cular ▁networks . ▁Even ▁nomin ally ▁dis ordered ▁( am orph ous ) ▁bor on ▁contains ▁regular ▁bor on ▁ icos ah ed ra ▁which ▁are , ▁however , ▁bond ed ▁randomly ▁to ▁each ▁other ▁without ▁long - range ▁order . ▁Cry st all ine ▁bor on ▁is ▁a ▁very ▁hard , ▁black ▁material ▁with ▁a ▁mel ting ▁point ▁of ▁above ▁ 2 0 0 0   ° C . ▁It ▁forms ▁four ▁major ▁polym orph s : ▁α - r hom bo hed ral ▁and ▁ β - r hom bo hed ral ▁( α - R ▁and ▁ β - R ), ▁ γ ▁and ▁ β - t et rag onal ▁( β - T ); ▁α - t et rag onal ▁phase ▁also ▁exists ▁( α - T ), ▁but ▁is ▁very ▁difficult ▁to ▁produce ▁without ▁significant ▁cont am ination . ▁Most ▁of ▁the ▁phases ▁are ▁based ▁on ▁B 1 2 ▁ icos ah ed ra , ▁but ▁the