- Not convertible; not capable of being transmuted,
changed into, or exchanged for, something else; as, one metal is
inconvertible into another; bank notes are sometimes inconvertible into
specie.
Meaning of 'inconvertible' (Princeton's WordNet)
1 . inconvertible
[ s]
Meaning (1): - not capable of being changed into something else
Example in sentence:
the alchemists were unable to accept the inconvertible nature of elemental metals