The robbery happed at approximately 8:00 p.m. Monday when a man walked into the store, located at 515 N. DuPont Highway.
The suspect approached the jewelry counter, handed the cashier a pillow case and instructed her to place the jewelry inside. He then opened his jacket and displayed a handgun in his waistband.
The gunman fled the store with an undisclosed amount of merchandise.
He is described as a white male, 5'10", 200 lbs, wearing a gray hooded sweatshirt, gray sweatpants, and white sneakers.
Anyone with information is asked to contact police at 302-736-7111. Callers may remain anonymous. Tips can also be submitted to law enforcement through tip lines maintained by Delaware Crime Stoppers at 1-800-TIP-3333 or on-line at www.tipsubmit.com.