"Freeze-Dried Specimens"

Porphyritic igneous rock containing biotite, feldspar, and hornblende.

Dark gray, with hornblende as the dominant mafic mineral.

Fine to medium-grained with biotite.

Dark gray, composed mostly of pyroxene and olivine.

Study the Formation of Different Igneous Rocks

Coarse grained and abundant in plagioclase feldspar.

Classic, very coarse-grained igneous texture.

Medium-grained with biotite.

Light gray, with flow structure.

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