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Dark gray with abundant gas pocket vesicles.

Pink and gray bands, with biotite; shows good foliation.

Abundant small black phenocrysts in a gray to brown matrix.

Light gray, fine small clasts.

Earthy, porous calcareous tufa.

Cemented glacial gravel.

Compact Plant Fiber Masses.

Black, soft; most widely mined.

Samples of Intrusive and Extrusive Igneous Rocks

Dark, coarse-grained, and composed chiefly of hornblende.

Foliated biotite, coarse, silvery gray with quartz-feldspar bands.

Perfect for Introductory Lessons on Metamorphic Rocks.

Represents a Wide Range of Depositional Environments and Rock Textures

Survey set improves student's recognition of all three major rock groups.

White, very dark green, and very dark red to light red granoblastic intergrowth of wollastonite, diopside, and andradite.

Gray and poorly sorted, with a gritty texture.