Article · Wikipedia archive · Last revised Jun 17, 2026

Foidolite

Foidolite is a rare phaneritic (coarse-grained) intrusive igneous rock in which more than 60% of light-coloured minerals are feldspathoids. 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.

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Jun 17, 2026
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Foidolite (sodalitolite variety) from Namibia source ↗
Thin section of foidolite under polarizing microscope. In the foreground there is a large yellow sodium pyroxene grain surrounded by fine grains. source ↗

Foidolite (/ˈfɔɪdəlaɪt/) is a rare phaneritic (coarse-grained) intrusive igneous rock in which more than 60% (by volume) of light-coloured minerals are feldspathoids.1 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.

See also

See also

References

References

  1. Le Maitre, R.W., ed. (2002). Igneous Rocks — A Classification and Glossary of Terms (2nd ed.). Cambridge: Cambridge University Press. pp. 4, 22, 24, 82. ISBN 0-521-66215-X.
External links
  • Foidolite (at University of Manitoba) - Retrieved 2009-05-15