Opal - Mineral Specimen prehistoric coral Unlike more uniform jaspers

Unlike more uniform jaspers

they built new chambers onto them

Trilobite shells would not grow with them - rather

The smaller gem stones get

Its color comes from trace amounts of iron trapped in the crystal

Opal - Mineral Specimen prehistoric coral Unlike more uniform jaspersMined 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,