Foidolite

Foidolite (pronEng|ˈfɔɪdəlaɪt) is a rare coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%. Crystals of alkali feldspar, plagioclase, biotite, amphibole, pyroxene and/or olivine may be present within the rock. The volcanic equivalents are termed "foidite" and "phonolitic or tephritic foidites".

Some foidolites are a potential source of aluminium.

ee also

*QAPF diagram