The finest opal known is obtained in the Upper Cretaceous formation at White Cliffs, near Wilcannia, New South Wales, and at these mines about 700 men find constant employment.
She was surprised to recognize the Council members, from tall, thin Opal to the Council members whose names she'd never learned.
Of Eperjes is situated the village of VdrSsvagas, which contains the only opal mine in Europe.
The mineral is also used in the production of opal glass and enamel ware.
The opal beds contain Cretaceous fossils such as Cimoliosaurus.
Blocks and logs of agate, chalcedony, jasper, opal and other silicate deposits lie in hundreds over an area of 60 sq.
For other forms of silica see OPAL and TRIDYMITE.