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.
Light gray, fine small clasts.
Brownish black, intermediate stage between peat and bituminous coal.
Classic, very coarse-grained igneous texture.
Gray, fine-grained, massive contact rock.
Fine crystalline, pure calcite.
Compact Plant Fiber Masses.
Dark gray, composed mostly of pyroxene and olivine.
Light gray, fine-grained, well-foliated, schistose.
Gray to brown mudstone with abundant silt.
