Definitions for "Boulder Opal"
A seam or patches of precious opal still attached to the host rock in which the opal formed. Highly valued and sought after for its brilliant colors and patterns. Most boulder opal is mined in Queensland, Australia. View our complete range of Boulder Opal.
Presented in one piece where the Opal is naturally attached to the host rock in which it was formed
is distinguished by the presence of host brown rock, usually ironstone, on the back of the opal; and is found almost exclusively in Queensland.