"Freeze-Dried Specimens"

Glassy; most specimens float in water.

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

Dark gray, composed mostly of pyroxene and olivine.

Study the Formation of Different Igneous Rocks

Coarse grained and abundant in plagioclase feldspar.

Dark gray, with hornblende as the dominant mafic mineral.

Fine to medium-grained with biotite.

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

Coarse-grained, with microcline, biotite and horblende phenocrysts.

Classic, very coarse-grained igneous texture.