"Freeze-Dried Specimens"

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

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.

Coarse-grained plagioclase and pyroxene with some olivine.

Classic, dark; from the Columbia Plateau.

Banded volcanic glass.

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