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

Synthesis methods to produce large and high-quality dia- mond for jewellery have been improved over

Purple jadeite, renowned for its distinctive purple hues and rich cultural connotations, is highly a