Olivine is a magnesium-iron silicate mineral, belonging to the orthorhombic crystal system. Brydningsindekset er 1.654-1.690, and the birefringence difference is quite high as 0.036. From the table of the gemstone, the ridgelines of the bottom facet become overlapping The double shadow is because of the high birefringence difference, spredningshastigheden er 0.020, [...]
