In 1831 Izumrudnye Kopi (Emerald mines) on the river Tokovaya were open by Yakov Kokovin, Director of the Ekaterinburg Lapidary Works and in 1833 the first alexandrite in the world was found in the mica schists of the Tokovaya river. In 1840 the largest alexandrite crystal cluster to date was found. Between 1840 and 1900, Izumrudnye Kopi was the primary source for alexandrite.
Izumrudnye Kopi (Emerald mines) is a mining region of rich berillium, emerald, alexandrite and phenakite deposits and includes granites of Aduiskii and Malyshevskii massives, rare metal pegmatites at Kvartalnoye and Lipoviy Log, the Youzhno-Shameiskoye deposit of molybdenum ore and the world largest deposits of emeralds: Malyshevskoye, Sverdlovskoye and Krasnobolotnoye deposits. The Sretenskoye deposit of emeralds became famous when Kozhevhikov discovered there the first Russian emeralds in December 1830. The first extracting period of this deposit was characterized by the mining of emerald-bearing sockets and prospecting works on occasional outcrops of emerald bodies. Aartels (Prospecting teams), diggers and Anglo-French company were all working deposits there from 1936 to 1940 and from 1969 to 1981.