1. a brownish or greenish iron silicate mineral that is a member of the olivine group
Usage: geology; mineralogy

Examples

• The volcanic rock contained crystals of fayalite.
• Fayalite is commonly found in iron-rich igneous rocks.
• The mineral specimen was identified as fayalite based on its composition.
• Fayalite forms at high temperatures in magmatic environments.
• The geologist collected samples containing fayalite from the lava flow.