A Faberge egg is among items stolen from a house in Bedfordshire following a house party while the homeowners were on holiday.
The theft is believed to have happened in Fairfield Road, Biggleswade, last month.
The owners returned to find extensive damage to their home and found a house party had been held and the egg and an iPod had been stolen.
The Faberge Egg is emerald green and set with diamonds in 18ct white gold.
The egg is 1.5 cm in height by 1cm wide and was designed to be attached to a pendant.
Police said it was possible jewellers or members of the public may have been offered the egg.
Officers also want to speak to anyone who attended a party in Fairfield Road between April and early May.
Det Con Mark Harrison said: "This jewellery is absolutely priceless to the owner, who was completely devastated to find it missing."