1 9 2 3 – 1 9 2 4 ▁Category : Pol it ics ▁of ▁the ▁London ▁Bor ough ▁of ▁Lamb eth ▁Category : Ind ian ▁Medical ▁Service ▁officers ▁Category : Ind ian ▁Army ▁personnel ▁of ▁World ▁War ▁I <0x0A> </s> ▁Bor on ▁is ▁a ▁chemical ▁element ▁with ▁the ▁symbol   B ▁and ▁atomic ▁number   5 . ▁Produ ced ▁entirely ▁by ▁cos mic ▁ray ▁sp all ation ▁and ▁super nov ae ▁and ▁not ▁by ▁stell ar ▁nucle os yn thesis , ▁it ▁is ▁a ▁low - ab und ance ▁element ▁in ▁the ▁Sol ar ▁System ▁and ▁in ▁the ▁Earth ' s ▁cr ust . ▁Bor on ▁is ▁concentr ated ▁on ▁Earth ▁by ▁the ▁water - sol ub ility ▁of ▁its ▁more ▁common ▁naturally ▁occurr ing ▁comp ounds , ▁the ▁bor ate ▁min er als . ▁These ▁are ▁m ined ▁industri ally ▁as ▁ev apor ites , ▁such ▁as ▁bor ax ▁and ▁k ern ite . ▁The ▁largest ▁known ▁bor on ▁depos its ▁are ▁in ▁Turkey , ▁the ▁largest ▁producer ▁of ▁bor on ▁min er als . ▁ ▁Element al ▁bor on ▁is ▁a ▁metal lo id ▁that ▁is ▁found ▁in ▁small ▁amounts ▁in ▁meteor oid s ▁but ▁chem ically ▁un comb ined ▁bor on ▁is ▁not ▁otherwise ▁found ▁naturally ▁on ▁Earth . ▁Indust ri ally , ▁very ▁pure ▁bor on ▁is ▁produced ▁with ▁difficulty ▁because ▁of ▁ref ract ory ▁cont am ination ▁by ▁carbon ▁or ▁other ▁elements . ▁Several ▁all otrop es ▁of ▁bor on ▁exist : ▁am orph ous ▁bor on