"Freeze-Dried Specimens"

Volcanic glass with snowflakes embedded throughout.

Shows porphyritic texture in a fine dark matrix abundant large feldspar phenocrysts. Hand specimen.

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

Grayish black trap rock.

Sale

Gray with line crinoid columnal fragments.

Glassy; most specimens float in water.

Gray to tan clastic rock made of silt sized particles.

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

Samples of Intrusive and Extrusive Igneous Rocks

White and black bands of quartz, feldspar, and biotite; typical foliation.