Rock Specimens

Everything You Need to Organize Your Specimens

Volcanic glass with snowflakes embedded throughout.

Hematite-cemented quartz; orthoquartzite.

Black, soft; most widely mined.

Gray to brown mudstone with abundant silt.

Classic, dark; from the Columbia Plateau.

Light gray, with flow structure.

Gray, fine, friable, with abundant small sanidine crystal fragments.

Chlorite-mica with perfect slaty cleavage.

Brownish black, intermediate stage between peat and bituminous coal.