It is proposed that the formation of the C-60 cage, named buckminsterf
ullerene, proceeds via the modified isoprene mechanism. Hence, it is p
ostulated that this molecule is an abiotic terpenoid. Similar mechanis
m is also proposed for the formation of the C59N cage. Since the therm
odynamic stabilities of C-60 and C59N cages are comparable, the reason
why the latter cage is not yet observed in the laboratory conditions
is probably related to its greater kinetic instability than that of bu
ckminsterfullerene.