Antiquary Ivan Efimov called the Constantine ruble the Holy Grail of collectors 
Konstantin's ruble and surviving copies of the first edition of “Travel from St. Petersburg to Moscow” by Alexander Radishchev. Ivan Efimov, chief expert of the Twelfth Chair auction house, told about this to Lente.ru.
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Treasures for nothing “Collector's holy grails.”
“The Constantine ruble is the rarest, most iconic Russian coin,” the expert says. It was minted in a short interregnum period after the death of Emperor Alexander II in 1825, when for two weeks his younger brother Constantine was mistakenly considered the heir.
Only a few Konstantin's rubles survived: three are in large museums, private collections. In 2021, one of the coins was purchased by the president of Lukoil, Vagit Alekperov, who paid $ 2.6 million for it.
“The most coveted book for a Russian collector is the rarest edition of Radishchev's Travel from St. Petersburg to Moscow, which was destroyed by order of Catherine II,” Yefimov believes.
Most of the circulation printed in the writer's home printing house, was destroyed after the empress's decree. He called the book “filled with the most harmful speculations, destroying public peace, belittling the respect due to the authorities.” The ban lasted until 1905.
Everyone knows such iconic things, but they may not get caught in a lifetime. That is, what's the point in looking for them. Yes, if you suddenly come across such an object, you will know what to do. But this is not enough. You can spend your whole life and not find anything
Ivan Efimov chief expert of the auction house “Twelfth Chair”
Earlier it was reported that the lost drawing of the famous Italian painter Giovanni Battista Tiepolo was found in the attic of an old house near Tauster, Northamptonshire, UK … The find was made by a woman whose family has owned the mansion for 300 years.