Nepheline syenite is a holocrystalline plutonic rock that consists largely of nepheline and alkali feldspar. The rocks are mostly pale colored, grey or pink, and in general appearance they are not unlike granites, but dark green varieties are also known. Phonolite is the fine-grained extrusive equivalent. ==Petrology== Nepheline syenites are silic...
Found on
http://en.wikipedia.org/wiki/Nepheline_syenite
medium- to coarse-grained intrusive igneous rock, a member of the alkali-syenite group (see syenite) that consists largely of feldspar and nepheline. ... [2 related articles]
Found on
http://www.britannica.com/eb/a-z/n/25
No exact match found.
