Beautiful black opal like this can only be found at Lightning Ridge, NSW, Australia.
The shape of opal. Our opal comes in Oval, Round, Teardrop, Square, Triangle and Free Shape.
Describes the arrangement of opal's play of colour. Please see Learn About Opal to understand more.
B1 is most desired and brightest to be seen, and B7 is most darkest / dullest of all.