Sig 15: Sokolnikov/Bogdanov 1 рубль золотом (gold ruble)
Details
Obverse: Front (vertical): Russian text; state emblem of the USSR; sheaf of wheat flanked by scythe, hoe, and two sickles
Reverse: Back (vertical): Armenian, Belorussian, Georgian, Russian, Tatar, and Ukrainian text; guilloches