Spontaneous Combustion and Coal Petrology - Coal and Peat Fires: A Global Perspective - page 58

Table 3.1.4b
The classification of bituminous coal lithotypes.

Lithotype and corresponding symbol
(Diessel, 1992) Lithotype (Hower, et al., 1990)* Description

Bright coal (vitrain) B Vitrain Vitreous to subvitreous luster; even to concoidal fracture; brittle; may contain

up to 10% dull bands less than 5 mm (3mm † )

40% dull bands less than 5mm (3 mm † ) Banded bright coal Bb Bright clarain Mainly vitrain containing 10 -

60% dull bands less than 5mm (3mm * )

Banded coal (duroclarain) Bd Clarain Contains 40 -

40% thin (less than 5mm (3 mm † )

Banded dull coal (clarodurain) Db Dull clarain Mainly dull coal containing 10 -

bright bands

Dull coal (durain) D Durain Matt luster and uneven fracture; contains less than 10% vitrain less than

5mm(3mm † )

Fibrous coal (fusain) F Fusain Dull with satin sheen; friable; may contain up to 10% of other coal lithotypes l

ess than 5mm (3mm * † )

Shaly coal Cs Bone Contains between 30 60% of clay and silt either in intimate mixture

with coal or in separate bands each less than 5 mm (3mm * † )

-

90% finely disseminated carbonaceous matter * Coaly shale, coaly mudstone, etc. Any sediment containing 60 -

Any sediment containing less than 10% carbonaceous matter * Shale, mudstone, etc.

Source : From Diessel, 1992; Hower et al., 1990.
* Noted in lithologic description at any recognizable thickness (Hower et al., 1990).
† Stopes, 1919.