Employees at Bellman's Jewelers in Manchester say Ronald Perley came in Thursday and was looking for an engagement ring.
Police say the 52-year-old Perley picked up a ring and ran toward the door.
Workers confronted him, saying they saw Perley put his hand to his mouth and swallow. He denied swallowing the ring.
Police got a search warrant and brought him to Elliot Hospital, where X-rays showed the 14-karat white-gold ring with princess-cut diamonds inside him.
Perley was arraigned on charges of theft and falsifying physical evidence. It wasn't immediately clear whether he had a lawyer. His $50,000 bail includes the ring's recovery.