Between 12.45pm and 12.57pm on Thursday May 3, offenders forced entry to a property in Singlets Lane via a side door.
After entering they carried out a search before taking a number of pieces of jewellery including a diamond platinum eternity ring, a single stone diamond ring and a Dreyfuss & Co rose gold watch with brown leather strap.
The break in is being investigated by the Dacorum Local Crime Unit, and Investigator Deborah Newsham said: “These items were of great sentimental value to their owners.
"They are distinctive and may have been offered to people for sale in suspicious circumstances. If you believe you have seen them since the break in, please get in touch.
“I would also like to ask anyone who saw anything suspicious in the area at the time including a dark coloured vehicle that was seen parked near to the house on the day of the burglary.”
Anyone with information is asked to contact police via the non-emergency number 101, quoting crime reference D1/18/3678.
Alternatively, you can contact the independent crime-fighting charity Crimestoppers anonymously on 0800 555 111 or through their Anonymous Online Form at www.crimestoppers-uk.org.
No personal details are taken, information cannot be traced or recorded and you will never need to go to court.