Peridot’s Gemological Properties:
Chemical: Mg2SiO4, Fe2SiO4
Formation: igneous rocks
RI: 1.654 – 1.690
Birefringence: 0.036
Optic Character: Biaxial Positive
Specific Gravity: 3.30
Crystal System: Orthorhombic
MOHs Hardness: 7
Wearability: Good