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Foid Gabbro

IUGS Definition ( QAPF Chart )

Foid Gabbro: “A collective term for basic alkaline plutonic rocks consisting of feldspathoids (10%-60% of the felsic minerals), calcic plagioclase and large amounts of mafic minerals.”
Photos
Chemistry
Typical Minerals
  • calcic plagioclase: labradorite or bytownite
  • feldspathoids
  • clinopyroxene: augite or diopside
  • accessory minerals: olivine, orthopyroxene, biotite, hornblende