"Microtomes and Microtome Assemblies"

Pale pink felsite, with small sanidine phenocrysts.

Lustrous, black 'hard coal'.

Gray to buff, with numerous ooliths and fossil fragments.

Shiny black volcanic glass showing conchoidal fracture and some spherulites.

Brownish black, intermediate stage between peat and bituminous coal.

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

Chlorite-mica with perfect slaty cleavage.

Gray to white, coarse crystalline, carbonate rock.

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

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