Opal - Mineral Specimen prehistoric coral When held up to the

When held up to the light

they built new chambers onto them

Though modest in size

Diameter: 23cm

Trilobite shells would not grow with them - rather

Opal - Mineral Specimen prehistoric coral When held up to theMined from: Coober Pedy, South Australia, Australia Description: This Australian opal specimen is presented in rough form within its natural host rock, showing pale grey to milky translucent opal along the edges with a soft waxy luster. The silica contrasts against a light, porous sandstone matrix, with iron rich staining creating subtle orange and reddish patches throughout. The opal itself shows conchoidal fracture surfaces and internal cloudiness,