"The Mystery of Lyle and Louise"

Pure, large, transparent-to-translucent cleavages, Mohs’ hardness of 4.

Lustrous, black 'hard coal'.

Shiny black volcanic glass showing conchoidal fracture and some spherulites.

Brownish black, intermediate stage between peat and bituminous coal.

Typical green-gray, fissile, clay-rich.

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

Chlorite-mica with perfect slaty cleavage.

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

Yellow to orange crystal with a glassy luster and smooth, often transparent appearance.

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

Silvery, paragranite and muscovite-rich with medium garnet crystals.

Gray to white, coarse crystalline, carbonate rock.

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

Nearly pure, green crystalline forsterite.

Brown, earthy, massive; used for yellow pigment.

Dark gray with abundant gas pocket vesicles.