"Metamorphic+Rocks"

Earthy, porous calcareous tufa.

4 pounds of limestone chips supplied in a box.

Light gray, fine small clasts.

Sawn and lacquered slab showing thinly bedded truncated layers in a well-cemented sandstone. Large hand specimen.

Buff-colored, coarse, detrital limestone, with cemented shell fragments.

Dark gray, composed mostly of pyroxene and olivine.

Specially selected topsoil, 1 lb.

Dark gray with abundant gas pocket vesicles.

Fine to medium-grained with biotite.

Well-cemented, medium-grained orthoquartzite.

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

Glassy; most specimens float in water.

Light gray, earthy.

Black, soft; most widely mined.

Dark gray, with hornblende as the dominant mafic mineral.

Light gray, with flow structure.