Typomorphic features of tourmalines of the Malkhan pegmatite field from the Irkutyanka vein

Euclase, monoclinic crystal system—is a seldomly occurring mineral and with a Mohs hardness of 7 a

Over the past several years, the market for pink-coloured rose quartz has been augmented by variants

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