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.