"Ward's Phenomena Lab Activities"

Typical green-gray, fissile, clay-rich.

Well-cemented, medium-grained orthoquartzite.

Black, soft; most widely mined.

Red, medium, to coarse-grained iron oxide cement; shows hematite bands.

Compact Plant Fiber Masses.

Light gray, earthy.

Brownish gray, kerogen-rich; commercial oil source.

Brownish black, intermediate stage between peat and bituminous coal.

Gray with line crinoid columnal fragments.

Light gray, fine small clasts.