Institute of the Earth’s Crust SB of RAS
Russian Federation

IMAEVA Lyudmila Petrovna, candidate of geological and mineralogical sciences, senior researcher

128 Lermontov Street, Irkutsk, 664033

Institute of Mineralogy, Geochemistry and Crystal Chemistry of Rare Elements RAS
Russian Federation

GUSEV Grigory Stepanovich, doctor of geological and mineralogical sciences, chief researcher

15 Veresaev Street, Moscow, 121357

Institute of the Earth’s Crust SB of RAS; Academy of Sciences of the Republic of Sakha (Yakutia)
Russian Federation

IMAEV Valery Suleymanovich, doctor of geological and mineralogical sciences, professor, chief researcher, 128 Lermontov Street, Irkutsk, 664033;

academic, 33 Lenin Avenue, Yakutsk, 677007