It happened just after 5:00 p.m. at the Viva La Vault in Fig Garden Village.
Employees say the crook had been inside the shop earlier Saturday afternoon, and when he returned he grabbed a ring display and ran.
Once the rings were swiped, an employee ran out the door screaming for someone to help stop the crook.
Chris Jones heard the screams while he was having dinner with his family nearby, and ran after the jewelry thief.
"I noticed some guy running really fast, in a nice dress shirt and everything. This one guy yelled 'hey grab him.' so I just threw off my jackets and everything and I just started chasing him down," said Jones. "Luckily, I caught up to him and I got the stuff that was stolen."
Viva La Vault Owner, Gary Yervan said, "He was dressed very nicely and pretty much fit in with the rest of the crowd that shops here at Fig Garden Village."
All but one ring was recovered from the robbery. Fig Garden Village security and Fresno Police now know what the suspect looks like because security cameras outside the shops were able to capture pictures of him. Those have not yet been released.
Watch the video for complete coverage from Action News Reporter Rick Montanez.