"The Mystery of Lyle and Louise"

Hematite-cemented quartz; orthoquartzite.

Gray, fine-grained, massive contact rock.

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.

Unpolished metamorphic rock with silky lusture, red-brown colour, and clear parallel intergrown quartz crystals.

Black, soft; most widely mined.

Lustrous, black 'hard coal'.

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

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