Two crooks posing as potential jewel buyers enlisted a street hawker to lead them into a Diamond District store, only to rob it at gunpoint yesterday.

Once inside Royal Gems Corp., 55 W. 47th St., at around noon, one of the thugs brandished a pistol. They bound three employees and a customer and made off with an undetermined amount of jewelry and cash, cops said.

Meanwhile the hawker — who goes by Mamodh — collapsed in apparent nervous breakdown, according to the security guard.

“Nobody got shot. The old dude (Mamodh) just got scared and fell down. Like a heart attack or something,” he said.

He was transported in stable condition to Roosevelt Hospital, according to FDNY officials.