opalised Fossils

opalised Fossils loose sale price & solid Australian black Opal Gemstone Information


The Australian opal fields were at one time under the sea, so opalised fossils are occasionally unearthed. As the ages passed and the seas began to recede, millions of sea creatures were isolated and marooned. Eventually the area dried completely and the inland is now a dry desert country.

In time the ground waters, holding silica solution, also evaporated. They left behind the phenomenon known as 'opal'. Hydrated silica was deposited in fissures in sandstone, or gypsum, and on jasper. It entered the shells of the stranded marine creatures. In some cases it even replaced the entire shell.

One can find opalised wood, prehistoric animal bones, sea creatures, full sea shells, skin shells, sponges, fish skeletons and even opalised stems of plants on the opal fields.