Sapphire and Common Opal Transparency
Similar to their colors, Sapphire and Common Opal transparency can also be used as criteria for their primary identification. Although transparency cannot be the only criteria for gemstone identification, it can efficiently used in gemstone grading. Talking about their transparency, Sapphire is Translucent, Transparent and Transparent to opaque while Sapphire is Translucent, Transparent and Transparent to opaque in appearance.