Troctolite Hand Sample
Troctolite Thin Section Photo

Troctolite

IUGS Definition ( Gabbroic Classification Chart )

Troctolite: "A variety of gabbro composed essentially of highly calcic plagioclase and olivine with little or no pyroxene."
Photos
Typical Minerals
  • calcic plagioclase: anorthite, bytownite, labradorite
  • olivine (commonly alters to serpentine): forsterite
  • accessory minerals: hornblende, biotite, chromite, spinel, enstatite (orthopyroxene)