Cannel coal or candle coal is a type of bituminous coal, also classified as terrestrial type oil shale. Due to its physical morphology and low mineral content cannel coal is considered to be coal but by its texture and composition of the organic matter it is considered to be oil shale. Although historically the term cannel coal has been used interchangeably with boghead coal, a more recent classification system restricts cannel coal to terrestrial origin, and boghead coal to lacustrine environments. Composition Cannel coal is brown to black oil shale. It comes from resins, spores, waxes, and cutinaceous and corky materials of terrestrial vascular plants, in part from Lycopsid (scale tree). Cannel coal was accumulated in ponds and shallow lakes in peat-forming swamps and bogs of the Carboniferous age under oxygen-deficient conditions. Thus cannel coal seams are shallow and often found above other deposits, while the coal itself, being rich in oils, burns long, with a bright yellow flame and little ash. The modern Lycopodiopsida relatives of these lycopsids (scale trees), with their similar high oil content, high surface area spores, are the source of highly flammable lycopodium powder. Cannel coal is also lower in fixed carbon than typical bituminous coal. It includes various amounts of vitrinite and inertinite. Analytically, cannel coal consists of micrinites, macerals of the exinite group, and certain inorganic materials. History Cannel coal has been used as jewellery since the neolithic, with pieces appearing in Scotland (often alongside jet) dating from the centuries before 3500BC. In England a member of the Bradshaigh family discovered a plentiful shallow seam of smooth, hard, cannel coal on his estate, in Haigh, Lancashire in the 16th century. The shallow depth at which it was found meant it was suitable for the simple surface mining methods available at that time. It could be worked and carved, and was prized for fireplaces as an excellent fuel that burned with a bright flame, was easily lit, and left virtually no ash. Cannel coal commanded a premium price as a grate fuel for use in home fireplaces. It burned longer than wood, and had a clean, bright flame. It is more compact and duller than ordinary coal, and can be worked in the lathe and polished. In the Durham coalfield and elsewhere carving cannel coal into ornaments was a popular pastime amongst the miners. The excess of hydrogen in a coal, above the amount