Rock Specimens

Brownish gray, kerogen-rich; commercial oil source.

Small, rounded pebbles and tightly cemented granules.

Dark, waxy, bitumin-rich.

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

Red-brown to gray, coarse-grained, containing feldspar and mica.

Fine, common limestone; massive, and will fizzle with HCl.

Indicative of Various Sedimentary Formation Processes

Gray to tan clastic rock made of silt sized particles.

Compact Plant Fiber Masses.

Chert is a microcrystalline, hard, silica mineral.