It happened at Pandora, on Westborough, around noon on Thursday November 23.
The woman was helped by a member of staff and selected and paid for two charms.
However, she is alleged to have concealed another two charms before leaving the store without making any effort to pay for them.
Police are appealing for anyone who can help identify the woman to call 101, select option 2, and ask for Nick Simpson. Or email [email protected]
Alternatively, contact Crimestoppers anonymously on 0800 555111.