▁the ▁bor on - 1 1 ▁nuc lei ▁are ▁available ▁commer cially . ▁The ▁ 1 0 B ▁and ▁ 1 1 B ▁nuc lei ▁also ▁cause ▁splitting ▁in ▁the ▁reson ances ▁of ▁attached ▁nuc lei . ▁ ▁Occ urrence ▁ ▁Bor on ▁is ▁rare ▁in ▁the ▁Un iverse ▁and ▁solar ▁system ▁due ▁to ▁trace ▁formation ▁in ▁the ▁Big ▁Bang ▁and ▁in ▁stars . ▁It ▁is ▁formed ▁in ▁minor ▁amounts ▁in ▁cos mic ▁ray ▁sp all ation ▁nucle os yn thesis ▁and ▁may ▁be ▁found ▁un comb ined ▁in ▁cos mic ▁dust ▁and ▁meteor oid ▁materials . ▁ ▁In ▁the ▁high ▁o xygen ▁environment ▁of ▁Earth , ▁bor on ▁is ▁always ▁found ▁fully ▁ox id ized ▁to ▁bor ate . ▁Bor on ▁does ▁not ▁appear ▁on ▁Earth ▁in ▁element al ▁form . ▁Ext rem ely ▁small ▁traces ▁of ▁element al ▁bor on ▁were ▁detected ▁in ▁L un ar ▁reg ol ith . ▁ ▁Although ▁bor on ▁is ▁a ▁relatively ▁rare ▁element ▁in ▁the ▁Earth ' s ▁cr ust , ▁representing ▁only ▁ 0 . 0 0 1 % ▁of ▁the ▁cr ust ▁mass , ▁it ▁can ▁be ▁highly ▁concentr ated ▁by ▁the ▁action ▁of ▁water , ▁in ▁which ▁many ▁bor ates ▁are ▁sol ub le . ▁It ▁is ▁found ▁naturally ▁combined ▁in ▁comp ounds ▁such ▁as ▁bor ax ▁and ▁bor ic ▁acid ▁( s ometimes ▁found ▁in ▁vol can ic ▁spring ▁waters ). ▁About ▁a ▁hundred ▁bor ate ▁min er als ▁are ▁known . ▁ ▁On ▁September ▁ 5 , ▁ 2 0