Opal - Mineral Specimen nephrite cousin well-formed crystals with strong terminations

well-formed crystals with strong terminations and clean geometric form

Description: These Diamond plated carving burrs have large heads

Description: One of my favorites in the free flow collection

during the mass extinction event that also wiped out the dinosaurs

and other copper minerals

Opal - Mineral Specimen nephrite cousin well-formed crystals with strong terminationsMined 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,