chrysocolla

from The Collaborative International Dictionary of English v.0.48

Chrysocolla \Chrys"o*col`la\, n. [L., fr. Gr. chryso`kolla gold
   solder; chryso`s gold + ? glue.] (Min.)
   A hydrous silicate of copper, occurring massive, of a blue or
   greenish blue color.
   [1913 Webster]