Black opal is the rarest and most valuable type of opal. Black opal is generally found as an opal bar (or bars) of various colours forming natural water horizontals in dark grey to black opal 'potch nobbies' or 'opal nodules'.

Few realize that 99.9% of the world's opal supply of this radiant, dark, lustrous gem is mined at only two pinpoints on the globe-- the Australian towns of Lightning Ridge in New South Wales (the black opal capital) and Mintabie in South Australia (Home of Mintabie black opal).

Each black opal has its own character that determine it's value to you and others. Usually the higher the price per carat the more lively and colorful the flash in the opal. The lively or colorful, even distribution, rarity of color or other unusual characteristics or combination of these items determine the price per carat.

Top quality opal is worth in excess of $30 000 US per carat. That would be some very special opal indeed.Other valuable forms of black opal include black opals fossils - ancient creatures and plants preserved in opal. This is black opal at it's very best!