AUBURN – A 1700s penny that’s nearly the size of a half dollar and, if authentic, could be worth a fortune surfaced in a jewelry and coin shop.

The 1793 coin is known by the “strawberry leaf” name because of a trefoil sprig on its tail side.

“As soon as I looked at it, I knew it was real,” said Dan Cunliffe Sr. of Republic Jewelry and Collectibles.

“It’s like the Holy Grail of coins,” said Cunliffe. Numismatists know of only three or four others in existence.

Cunliffe did not reveal the coin owner’s name in order to protect her privacy.

The coin was in the possession of the owner’s family since 1941, when it was purchased by a collector for $2,750, the owner told Cunliffe.

Cunliffe said the coin is to be auctioned off shortly after Thanksgiving by American Numismatic Rarities of Wolfeboro, N.H. The auction will be part of the Baltimore Coin Convention.

“I expect [the strawberry leaf cent] will draw bids of six figures,” Cunliffe said.