lamprophyre
/ˈlamprəˌfʌɪə
/noun [mass noun] Geology
A porphyritic igneous rock consisting of a fine-grained feldspathic groundmass with phenocrysts chiefly of biotite.It has also been found in silica-poor igneous rocks, such as syenite, nepheline syenite, serpentinite, and lamprophyre....
- The only known igneous rocks in the area are Permian periodotite and lamprophyre dikes as well as diatremes of ultramafic composition associated with the Fluorite district.
- Subordinate volumes of carbonatite and lamprophyre magmas are also present.
Origin
Late 19th century: from Greek lampros 'bright, shining' + porphureos 'purple'.