BGS Rock Classification Scheme
Durain - A type of bituminous-coal, classified according to lithotype. It consists of dark grey to black bands with a dull to slightly greasy lustre. The material is relatively hard compared to other lithotypes, and tends to break into large blocky fragments. Durain may be confused with impure coal which is also dull and hard, but it can be distinguished by its lower density. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10.
| Code | DURAIN |
|---|---|
| Description | Durain - A type of bituminous-coal, classified according to lithotype. It consists of dark grey to black bands with a dull to slightly greasy lustre. The material is relatively hard compared to other lithotypes, and tends to break into large blocky fragments. Durain may be confused with impure coal which is also dull and hard, but it can be distinguished by its lower density. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. |
| Qualifiers | No qualifiers currently exist. |
| Definition | Bituminous coal lithotype. Dark grey/black band/layers, dull to greasy lustre. Harder than vitrain/clarain/fusain, breaks into large blocky fragments. Looks similar to impure coal but has lower RD. |
| Linked data | http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/DURAIN |
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.