Fayalite
ID: 112
Fayalite
Chemical Formula
Fe2SiO4
Hardness (Mohs)
6.5
Crystal System
Orthorhombic
Streak
Light brown
Luster
Vitreous to greasy
Diaphaneity
Transparent to translucent
Color
Brown, yellowish-brown, reddish-brown, black
Crystal Habit / Mode of Occurrence
Prismatic, tabular, or equant crystals; massive, granular
Fun Facts
Fayalite is the iron-rich endmember of the olivine solid solution series.