"Avantor"

Fightly cemented, medium-to-coarse quartz grains.

Light gray, with flow structure.

Gray, fine to medium-grained “Berea grit”.

Hematite-cemented quartz; orthoquartzite.

Foliated biotite, coarse, silvery gray with quartz-feldspar bands.

Typical green-gray, fissile, clay-rich.

Brownish gray, kerogen-rich; commercial oil source.

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.