"Avantor"

Light gray, fine small clasts.

Brownish black, intermediate stage between peat and bituminous coal.

Classic, very coarse-grained igneous texture.

Gray, fine-grained, massive contact rock.

Fine crystalline, pure calcite.

Compact Plant Fiber Masses.

Dark gray, composed mostly of pyroxene and olivine.

Light gray, fine-grained, well-foliated, schistose.

Gray to brown mudstone with abundant silt.

Gray and poorly sorted, with a gritty texture.

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

Black, fissile; commonly with carbonized fossil plant impressions.

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

Enough for 12 groups!

Demonstrate the Process of Learning

Two investigations teach the principles of chromatography.