Gilson Created Opal, are grown in a laboratory from genuine natural opal. It is not plastic or resin based like most other simulants. The process was invented many years ago by scientist Pierre Gilson who keeps it a well guarded secret. Black Opals are the most coveted of all opal varities and at its highest can fetch phenominal prices on the market. The black in an opal refers to its dark body tone however at times it can be crystal or opaque. The rarest colour is red, followed by green and orange with blue being the most common. Semi-black opals have an inherent darkness in it's body colour when viewed against a white background. Mid-grey stones are termed as semi-black. Around 70% of the black opals come from Lightning Ridge and are much less from the Mintabie opal mines. These are the two areas in Australia producing the majority of black opal.
Black with Vibrant Oranges, Blues, Greens and Reds, Good Cut, Good Polish.
Moh's Hardness = 5 - 6.5.
Moh's Hardness = 5 - 6.5.
