A thief posing as a husband-to-be got away with an $11,000 diamond from a Queens jewelry store, police said Tuesday.

The fraudster walked into a Zales Jewelry Store at the corner of 31st and Steinway avenues in Long Island City around 11 a.m. Jan. 23, asking a 49-year-old employee for help finding an engagement ring, police said.

The thief swapped the high-priced rock for a fake one when the saleswoman was distracted, police said.

He fled the store with the diamond.

A media representative for Zales was not immediately available to comment.