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

The iron-titanium charge transfer (Fe-Ti CT) is mentioned in numerous articles as the source of the

In recent years, an increasing number of sources of fei cui, such as Guatemala, Italy and Russia, ha

The Salininha emerald deposit located in the municipality of Pilão Arcado, Bahia State, represents