The Collaborative International Dictionary of English v.0.48:

Cadmia \Cad"mi*a\, n. [L. cadmia calamine, Gr. ?. Cf.
   Calamine.] (Min.)
   An oxide of zinc which collects on the sides of furnaces
   where zinc is sublimed. Formerly applied to the mineral
   calamine.
   [1913 Webster]