Black opal is the rarest and most valuable type. It is generally found as a bar (or bars) of various colours forming natural water horizontals in dark grey to black "potch nobbies" or "nodules". The unique patterns are as complex as an artist's imagination.
|99.9% of the world's supply of this radiant, dark lustrous gem is mined at only two tiny pinpoints on the globe - Lightning Ridge and Mintabie, Australia.|
|Coober Pedy, an Aboriginal name meaning "White man in a hole", adequately describes the mines and miners' dwellings - burrows dug into the scarp, in order to escape the soaring temperatures of the day and the freezing winds at night.|