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

Larimar, a massive blue variety of the mineral pectolite, belonging to the wollastonite group of min

Over the past few years we have been seeing more and more lower quality stones in the lab. The reaso

Malacacheta, located in Minas Gerais, Brazil, is renowned for its alexandrite deposits and com-plex