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

Museums are unique repositories of international treasures. They are also places of active research,

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

Amber was recently discovered by local coal miners at the Thanbaya Gaing Coal mine located 6.5 km no