"PARKWAY PLASTICS, INC."

Light gray, with flow structure.

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

Gray andesite with phenocrysts of felspar and/or hornblende.

Classic, dark; from the Columbia Plateau.

Coarse, 'salt and pepper': dark pyroxene and light andesine. Provides perfect representation of an intermediate igneous rock.