17. Nov IGC 2025 Blue sapphire from Malacacheta of Minas Gerais, Brazil Masaki Furuya Download Pdf Sapphire
17. Nov IGC 2025 Pink-orange gem quality euclase from Bahia, Brazil Euclase, monoclinic crystal system—is a seldomly occurring mineral and with a Mohs hardness of 7 a Read More Elodie
17. Nov IGC 2025 On the nature of blue rose quartz Over the past several years, the market for pink-coloured rose quartz has been augmented by variants Read More Laurent Cartier
17. Nov IGC 2025 Zoisite and its many color The mineral zoisite is a calcium alumosilicate belonging to the class of silicates, more exactly sor Read More Elodie
