A 0.45 carat natural ruby is inserted on the central label. Corundum, red, pear. Refractive index: 1.760 - 1.770, birefaction: 0.010, specific gravity: 4.00.
A 0.45 carat natural ruby is inserted on the central label. Corundum, red, pear. Refractive index: 1.760 - 1.770, birefaction: 0.010, specific gravity: 4.00.