Eleven commemorative platinum coins with a 150-ruble face value were produced in the Soviet Union between 1977 and 1991. The first 5-coin set was dedicated to the Moscow Olympics in 1980 and was a part of a large minting which included various copper-nickel coins (8.5 million pcs.), fourteen silver coins of 5 and 10 rubles (16.67 and 33.3 g respectively) and six 100-ruble gold coins (17.3 g). These "XXII Summer Olympic Games" platinum coins depicted the emblem of the Olympics and fragments of the ancient Olympic Games, and were issued in the period 1977–1980 in the two versions, proof and uncirculated. The proof minting technique (coins with mirrored background and frosted image) was first introduced in the Soviet Union in 1977 specifically for the Olympic commemorative series, and its quality (especially of the snow-like images) has been praised by experts.