Peter I 2 Kopeks

What always surprises me about Peter I's 2 kopek coins is how they were struck from copper planchets weighing up to 20 grams, making a coin worth two kopeks feel like it could double as a doorstop.

Production ramped up in the early 1700s at the Moscow Mint, as part of the tsar's push to overhaul Russia's currency. These pieces featured simple designs, like the double-headed eagle and Peter's monogram, but variations in die quality meant not every strike was perfect. Mintage figures are hazy; records from that era burned in later fires.

One dry observation: If you think modern pennies are heavy, try carrying a pocketful of these without breaking a sweat.

Weights and dates varied, but most circulated until the 1720s, when economic shifts rendered them obsolete. What we don't know is exactly how many ended up melted down for cannons or household items.