This is a cut and polished natural black opal from the Lightning Ridge mines in New South Wales. We cut it into a triangular shape, which meant that we had to leave a bit of the black backing stone on one side. This makes the stone all the more interesting as you can see how the opal layer has formed on the ironstone. The opal layer itself displays a vivid green fire. The stone is 1.2cm high and 9mm wide at its base. It weighs 1.9 carat. An unusual stone, which would look great when set in a pendant, or it could just be kept as a mineral sample.