"Avantor"

Slaty cleavage; contains hematite.

Chlorite-mica with perfect slaty cleavage.

White, very dark green, and very dark red to light red granoblastic intergrowth of wollastonite, diopside, and andradite.

Define and compare ways organisms have been preserved.

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.

Small, rounded pebbles and tightly cemented granules.