Crowned double-headed eagle with wings displayed, holding scepter and orb with cross, coat-of-arms of Moskva framed by Order of St. Andrew on breast; arms of Kazan, Astrakhan, and Novosibirsk on right wing, Kingdom of Poland, Caucasus, and Grand Duchy of Finland on left. Imperial crown above, initials А-Ч (mintmaster Alexei Chadov) below.
Description reverse
In five lines 3 РУБЛЯ. 20 ZlOTYCH. 1840.
Below mintmark C.П.Б.
Around ЧИСТАВО ЗОЛОТА 81 ДОЛЯ.
Reference
Poland. Congress Poland. 20 Zloty/ 3 Rubles 1840, Saint Petersburg. CoCo PL-1840-0002.