Shining light on “480 nm band” diamonds: Gemmological characteristics of an unusual group of diamonds with yellow and red luminescence

Corundum, encompassing the highly prized ruby and sapphire varieties, stands as a cornerstone of the

pinel is a highly valued gemstone, with its color and quality influenced by trace-element chemistry

Jade or "Fei Cui" are trade names for a stone that typi- cally contains only one or more main minera