Padparadscha Sapphire & heat treatment
Stephen Kennedy
Blue sapphire from Malacacheta of Minas Gerais, Brazil
Malacacheta, located in Minas Gerais, Brazil, is renowned for its alexandrite deposits and com-plex
Cross-Cultural Provenance and Characterization of Turquoise Artefacts: A Multi-Analytical Non-Destructive Study of Reshui Tomb Cluster, China (744 AD) and Tepeh Zagheh, Iran (5200–4200 BCE)
Turquoise has long held considerable cultural, economic, and symbolic significance across ancient ci