BGS Rock Classification Scheme
Crystalline igneous rock - Rock comprised essentially of interlocking crystals and/or glass. In the Rock Classification Scheme, this class includes normal crystalline igneous rock, and exotic crystalline igneous rock. British Geological Survey Research Report RR/99/06, section 1.3 and fig. 1.
| Code | CIR |
|---|---|
| Description | Crystalline igneous rock - Rock comprised essentially of interlocking crystals and/or glass. In the Rock Classification Scheme, this class includes normal crystalline igneous rock, and exotic crystalline igneous rock. British Geological Survey Research Report RR/99/06, section 1.3 and fig. 1. |
| Qualifiers | No qualifiers currently exist. |
| Definition | Crystalline intrusive/extrusive rock, includes both chemically & mineralogically normal & exotic, crystal size not defined, includes most of the volume of igneous rocks |
| Linked data | http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/CIR |
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.