BOGHEAD (from the name of the Boghead village, within Scotland * EN: boghead, algal coal; DE: Bogheadkohle; FR: boghead; ES: bogue; RU: богхед) is the coal of the class of the fossil coals (sapropelites), which have formed themselves mainly as the result of the metamorphosis of the remains from the simplest animals and plant organisms. The colour is brownish-black, sometimes olive. The fracture is conchoidal, the surface of the fracture is matte. It is characterized by the increased density, viscosity, and hydrogen content (8-12%). The content of the volatile substances is 60-70%. During the distillation, it provides the high yield of the primary tar.

It is represented by the clusters of the remains of the algae, namely, of the thallomite-alginite (GOST 9414-60, governmental standard), or alginite-thallomite (according to the system of the Geological Institute within the Academy of Sciences of the USSR), of the varying degree of preservation and size, and also by the non-significant quantity of the gelificated major mass; there is noted the almost complete absence of the forming elements of the higher plants, namely, of the covers, spores, and so on. There are known the deposits of the boghead within the near-Moscow and Irkutsk coal basins, and within the other regions of the USSR, and also within the series of the coal basins within the Great Britain and France, where they form the interlayers within the layers of the humolites, but sometimes the independent layers.

The boghead is the valuable raw material for the obtainment of the liquid fuel, lubricating substances, valuable tar, which is free of the phenols and asphaltenes, and so on.