Opal - Mineral Specimen green crystal Geological Age: 65

Geological Age: 65

overall basaltic composition with Fe

and also filter feeders

I often cut the bristles with scissors on bristle brushes to help them fit in tighter areas

Opal - Mineral Specimen green crystal Geological Age: 65Mined from: Coober Pedy, South Australia, Australia Description: This Australian opal is shown in rough form, still partially embedded in its host rock, with a mix of pale blue grey translucent silica and earthy red brown ironstone staining. The surface shows natural weathering and pitting, with areas of exposed opal displaying a waxy to slightly glassy luster. Subtle internal color shifts are visible in the cleaner sections, with faint hints of blue