carbon from the allende meteorite is not graphite but carbyne ( triply bonded elemental carbon ) , inasmuch as on heating to 250 degrees to 330 degrees c it releases mainly triply bonded fragments : - ( c identical withc ) ( n ) , - with n = 1 to 5 , and - ( c identical withc ) ( n ) -cn , with n = 1 to 3 .
C0302933
graphite
C0007009
elemental carbon