BGS Rock Classification Scheme

Granite, pegmatitic

Code PGGN
Description Granite, pegmatitic
Qualifiers pegmatitic      
Definition Coarse-grained, av. between 2-16mm normal crystalline intrusive rock containing markedly coarser (>16mm) regions of the same composition; quartz 20-60% of QAPF, feldspar 35-90% alkali feldspar, +/- mica/amphibole
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/PGGN

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.