Source : Webster's Revised Unabridged Dictionary (1913)

Inconvertibility \In`con*vert`i*bil"i*ty\, n. [L.
   inconvertibilitas.]
   The quality or state of being inconvertible; not capable of
   being exchanged for, or converted into, something else; as,
   the inconvertibility of an irredeemable currency, or of lead,
   into gold.

Source : WordNet®

inconvertibility
     n : the quality of not being exchangeable; "the inconvertibility
         of their currency made international trade impossible"
         [ant: {convertibility}]