"gel box"

Light gray, fine-grained, well-foliated, schistose.

Gray to brown mudstone with abundant silt.

Red-brown to gray, coarse-grained, containing feldspar and mica.

Black, fissile; commonly with carbonized fossil plant impressions.

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

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

Feldspar group; calcium end member plagioclase crystals in pyroxene matrix.

Blue fluorapatite, pure crystalline, Moh's hardness of 5.

Feldspar group; pink cleavages showing perthitic texture, common potassium feldspar, Mohs’ hardness of 6.

White, massive, coarse crystalline vein, Mohs’ hardness of 7.

Pure translucent to white, rhombic cleavages, Mohs’ hardness of 3.

Nearly pure, green crystalline forsterite.

Coarse, 'salt and pepper': dark pyroxene and light andesine. Provides perfect representation of an intermediate igneous rock.

Amphibole group; black, coarse, massive.

Feldspar group; good cleavages of pure soda lime feldspar; most show twinning and labradorescence.

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