The crime happened at the Valero gas station on Olive Avenue near R Street around 4:30 a.m.
Officers say a man wearing all black with a red bandana over his face pointed a gun at the store clerk and demanded the gold chain she was wearing. She tried to give him change from the register instead, but he lunged at her and ripped the chain from around her neck. The suspect then ran away from the scene.
Anyone with information is asked to call the Merced Police Department Tipster Line at (209) 385-4725.