The Collaborative International Dictionary of English v.0.48:

Lithia \Lith"i*a\ (l[i^]th"[i^]*[.a]), n. [NL., from Gr. li`qos
   stone.] (Chem.)
   The oxide of lithium; a strong alkaline caustic similar to
   potash and soda, but weaker. See Lithium.
   [1913 Webster]

   Lithia emerald. See Hiddenite.
      [1913 Webster]