Opal
Overview
Opal is made of tiny spheres of silica stacked in a regular pattern, with water trapped between them. When light passes through this structure it splits into flashes of spectral color, an effect called play of color. Opal has no crystal structure, which is why gemologists describe it as amorphous.
Because opal contains water and is relatively soft, it needs care: sudden temperature changes and knocks can damage it.
Origins
Australia has long produced most of the world’s precious opal, including the prized black opal of Lightning Ridge. Ethiopia has become an important source since 2008, and Mexico is known for its fire opal.
The full opal guide is being written by the Tavira Gems Editorial Team.
Last updated November 2, 2026 by the Tavira Gems Editorial Team.