BGS Rock Classification Scheme

Black-lignite - A type of lignite. It is dark brown to black with a silky lustre, and much harder than brown-lignite. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10.

Code BKLIGN
Description Black-lignite - A type of lignite. It is dark brown to black with a silky lustre, and much harder than brown-lignite. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10.
Qualifiers No qualifiers currently exist.
Definition Lithified, dark-brown/black, silky lustre mixture of range of plant debris many individually discernable. Fine 0.032-0.25mm organic matrix. 60-75% carbon, dry, ash-free. Volatiles 46-63%. Partly carbonised, cracks/breaks on drying. Hardness >brown-lignite
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/BKLIGN

CAVEAT

"Thumbnail" definitions attached to some of the table entries are an interim attempt to provide simple short descriptions of the "unqualified" rock types presented within the BGS Rock Classification Scheme. Every effort has been made to ensure accuracy and consistency but minor contradictions or omissions might be present. The BGS welcomes any feedback pointing out such minor imperfections and/or providing constructive comment and suggestions for improvement of the definitions. In the first instance such feedback should be directed to Dr Tim McCormick.