"Avantor"

Light gray, compact, hard, opaque, microcrystalline silica mineral.

Clear, euhedral points and sections.

Pure, bright yellow, Frasch sulfur.

Gemmy, sherry-colored crystals and sections approximately 3/8– 1/2"

Cleaned, pure, bright, metallic native copper.

Massive, chlorite-rich.

Well-cemented, medium-grained orthoquartzite.

Chlorite-bearing.

Dark, coarse-grained, and composed chiefly of hornblende.

Gray andesite with phenocrysts of felspar and/or hornblende.

Glossy green dunite (olivine) inclusion in non-genetically related basalt. Average size: 3" x 4".

Sawn and lacquered slab showing thinly bedded truncated layers in a well-cemented sandstone. Large hand specimen.

Classic, dark; from the Columbia Plateau.

Lustrous, black 'hard coal'.

Black, soft; most widely mined.

Cemented glacial gravel.