A national symbol must have broad relevance. In Australia, commercial opal production occurs in New South Wales, Queensland, ...

Meline: A pearl is one of the most complex gems to assess the value of. One factor is whether it's natural or cultured. Natural pearls are harder to find, making them worth more money. The vast ...

Opals, as hydrated forms of silica, encompass a wide range of materials formed by both biogenic and diagenetic processes. The genesis of opal involves precipitation from silica‐rich fluids and ...

"That's just wild." Common opal can be found all over the world, but the precious, coloured opal of Lightning Ridge is exceedingly rare. The traditional owners of this land have a longstanding ...