Modern Cultivation of Freshwater Pearls in China: Advances in Materials, Technique

For many, fossiliferous tree resin, primarily amber, gained wide visibility to the public in 1993 wh

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

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