"Igneous Rock Specimens"

Abundant small black phenocrysts in a gray to brown matrix.

Gabbro is Mafic igneous rock formed deep underground consisting of olivine and pyroxene.

Anorthosite is an intrusive, igneous rock consisting of predominantly plagioclase feldspar.

Sale

Classic, very coarse-grained igneous texture.

Dark gray, composed mostly of pyroxene and olivine.

Gray-to-brown basaltic, with over 50% vesicles.

Pale pink felsite, with small sanidine phenocrysts.

Glassy; most specimens float in water.