"Specimens"

Feldspar group; white to gray, sodium plagioclase cleavages; some faces may show twinning.

Feldspar group; greenish gray alkali feldspar, coarse crystalline, some iridescence.

Spinel group; iron-black, massive; natural magnet.

Pyroxene group; dark green, pure cleaved fragments.

Deep purple crystal clusters.

Deep blue, massive, with nepheline; key feldspathoid.

Dark brown to black; polycrystalline zinc ore.

Exemplary display of hexoctahedral crystal shape.

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

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.