They weren’t wooden nickels — but a Queens man still took the world’s largest coin dealer for $31,000 when he sold three supposedly rare gold US coins that were actually Chinese counterfeits, according to a new lawsuit.

Boris Koyen Aminov, 37, of Rego Park, sold Heritage Auctioneers & Galleries on Park Avenue the three gold coins in April.

Aminov identified himself as a coin collector and presented supposedly rare coins to Heritage for sale, the auction house says in court papers filed yesterday in Manhattan Supreme Court.

“Heritage believed and relied upon Aminov’s representations that these were rare coins with a very high value,” Heritage says.

But shortly after Aminov cashed his $31,000 check for the three coins, “Heritage discovered that the coins were fake and virtually worthless.”

The “collector” had offered the purportedly extremely valuable coins to the auction house in coin-holders bearing what looked like the logo of the Professional Coin Grading Service.

The two most unusual coins were $5 gold Indian heads from 1909 stamped with an “O” for the New Orleans Mint. These pieces, when authentic, have a selling price of around $690,000, and only an estimated 10 originals are known to be in existence.

Heritage President Greg Rohan told The Post that Chinese counterfeiters had altered the “D” on real 1909-D $5 coins from the Denver Mint, which are much more pieces, to look like an “O.”

“These are really, really good counterfeits,” Rohan said.

The three coins actually have a value of about $1,200 total based on their gold content.

“Our expert who got fooled in New York is a top expert,” Rohan said. “We virtually never buy fakes, but these fakes were that good.”

It’s unclear whether Aminov knew the coins were fakes. Rohan claims the seller changed his story when confronted about their authenticity, first saying the pieces were from his grandfather, then explaining that he inherited them from an uncle.

Aminov first told Heritage he would refund the money, but then reneged because he had already spent the $31,000, according to the lawsuit.

Aminov did not return calls seeking comment.

Heritage is suing Aminov for a full refund.