noun
- Plural of fayalite; iron silicate minerals of the olivine group, typically dark green or black in color, found in igneous rocks.
Usage: mineralogy; geology; technical
Examples
- Fayalites are commonly found in iron-rich igneous rocks.
- The geologist identified fayalites in the basalt sample under the microscope.
- Fayalites have a higher iron content compared to other olivine minerals.
- These fayalites crystallized during the cooling of the magma.