Head of the “Coins and Medals” firm, Igor Lavruk, told Itar-Tass news agency that coins were rarely made in the form of a square in Russia. The item on display was struck in 1726 in the central Russian city of Yekaterinburg, which was founded only three years prior to the issue of the unusual square coin.

However, it’s not the priciest item to be featured at the exhibition. There is also a silver coin made in 1896 featuring the image of Tsar Nicolas II. The former equivalent of 10 rubles has been estimated at $132,000. One hundred and twenty-five copies of the coin were made, but were never put into circulation.