A variety of coal that resembles a carbonaceous shale in outward appearance. It is fine-grained, brown to black, and tough, and breaks with a conchoidal or subconchoidal fracture. The name torbanite is derived from the initial discovery site of the material in 1850 at Torbane Hill, Linlithgowshire, Scotland. Torbanite is synonymous with boghead coal and is related to cannel coal. It is derived from colonial algae identified with the modern species of Botryococcus braunii Kütz and antecedent forms.