"VWR"

Samples of Intrusive and Extrusive Igneous Rocks

Includes: six each of obsidian, pumice, and basalt. Set of 18.

Common rocks and minerals for testing and identification studies are 2–3cm each.

Abundant small black phenocrysts in a gray to brown matrix.

Dark gray with abundant gas pocket vesicles.

Pale pink felsite, with small sanidine phenocrysts.

Classic, very coarse-grained igneous texture.

Dark gray, composed mostly of pyroxene and olivine.

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

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

Study the Formation of Different Igneous Rocks

Coarse-grained plagioclase and pyroxene with some olivine.

Dark gray, with hornblende as the dominant mafic mineral.

Fine to medium-grained with biotite.

Medium-grained with biotite.

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

Shiny black volcanic glass showing conchoidal fracture and some spherulites.