A Peter II gold ducat dating to 1729 is to lead the third instalment of the Eric P Newman collection sale at Heritage Auctions in New York on January 14-16.
It will carry an estimate of $45,000-65,000.
Peter II (1715-1730) was crowned emperor of Russia in 1727 and ruled for just three years before dying of smallpox. He spent the majority of his life in seclusion after his father, Prince Alexis, was accused of treason and imprisoned by Peter II's uncle, Peter the Great.
The two main issues of the coin show the young ruler with a hair ribbon or without - the "no ribbon" variety being the rarest.
The coin is in excellent condition, displaying a fine lustre and a solid strike.
A Republic of Ecuador gold 4 escudos dating to 1841 is valued at $25,000-30,000.
The coin was minted under the rule of Juan Jose Flores and was of low quality, making it relatively easy to forge.
Despite numerous attempts to deter counterfeiters, including the addition of text around the rim of the coin, many in Ecuador turned to the use of merchant tokens.
Only four examples of the 4 escudos are known to have survived to the present day, with this being the finest example in terms of condition and strike.
Other coins in the sale include an Italian 1902 Vittorio Emmanuele III 20 lire, which is estimated to make $25,000-35,000.
A Pedro I gold coin will be offered at another numismatic sale at Heritage Auctions in January.
We have a selection of rare coins for sale.
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