Archive for the Olivine Group Category
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Refractive Index : 1.690 – 1.654 (+0.020 – 0.020)
Optical Characteristic : DR, biaxial positive or negative
Specific Gravity : 3.34 (+0.14 – 0.07)
Formula : Mg2SiO4-Fe2SiO4
Crystal System : Orthorhombic
Variety/Species : Peridot
Species/Group : Olivine group
Birefringence : 0.035 to 0.038
Dispersion : 0.020
Hardness : 6.5 to 7
Toughness : Fair to good
Ultrasonic : Risky
Steam : Never
UV Long : Inert
UV Short : [...]