"WardsSci000450"

Light gray, with flow structure.

Banded volcanic glass.

Dark gray with abundant gas pocket vesicles.

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

Porphyritic igneous rock containing biotite, feldspar, and hornblende.

Pegmatite is igneous rock similar to granite but with larger crystals.

Sale

Pumice is light colored glassy rock that floats in water.

Grayish black trap rock.

Scoria is a dark-colored rock formed from lava with a high gas content.

Abundant small black phenocrysts in a gray to brown matrix.