"The Mystery of Lyle and Louise"

Hematite-cemented quartz; orthoquartzite.

Chlorite-bearing.

Lustrous, black 'hard coal'.

Black, soft; most widely mined.

Slaty cleavage; contains hematite.

Gray to buff, with numerous ooliths and fossil fragments.

Gray, fine-grained, massive contact rock.

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.