A. K. Litvinenko
Sergo Ordzhonikidze Russian State University for Geological Prospecting
Russian Federation

Andrei K. Litvinenko — Dr. Sci. (Geol.-Min.), Professor of the Department of Mineralogy and Gemmology

23, Miklukho-Maklaya str., Moscow 117997

D. B. Vandanova
Gokhran of Russia
Russian Federation

Darima B. Vandanova — Leading Expert of the Gemstone Research Laboratory of the Research Department of the Scientific and Technical Department 
.
14, 1812 Goda str., Moscow 121170

O. A. Shilova
Gokhran of Russia
Russian Federation

Oksana A. Shilova — Chief Expert of the Gemstone
Research Laboratory of the Research Department of
the Scientific and Technical Department

14, 1812 Goda str., Moscow 121170

S. B. Pakhomova
Gokhran of Russia
Russian Federation

Svetlana B. Pakhomova*  — Chief Expert of Gemstone Research Laboratory of the Research Department of the Scientific and Technical Department

14, 1812 Goda str., Moscow 121170