"Ward's Phenomena Lab Activities"

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

Grayish black trap rock.

Dark gray, with hornblende as the dominant mafic mineral.

Fine to medium-grained with biotite.

Abundant small black phenocrysts in a gray to brown matrix.

Classic, dark; from the Columbia Plateau.

Medium-grained with biotite.

Light gray, with flow structure.

Dark gray, composed mostly of pyroxene and olivine.

Samples of Intrusive and Extrusive Igneous Rocks