The occupants of the flat in Avontoun Park, Linlithgow, returned home to find their flat had been broken into and several items stolen.
"It’s believed the break-in and theft occurred between the hours of 9am and 11am on Monday.
A number of personal items have been taken.
Two wallets have been stolen and valuable pieces of jewellery have been stolen, including two diamond rings and a ruby ring. The items equate to around a four-figure sum of money.
Detective Constable Lynn Myles said: “Many of the stolen items of jewellery have great sentimental value to the owners and they are devastated at them being taken.
"I would ask anyone who has any information on this crime to contact us.
"If anyone has any private CCTV or ring footage, please check it as it could hold vital information and could lead us to identifying the suspects.”
She added: “I would also urge people to be aware of anyone selling items of jewellery, it could be stolen. If you have any information, please get in touch with us. Your information could contribute to the items being returned to their rightful owners.”
Anyone with information is asked to call Police Scotland via 101, quoting incident number 1017 of 17 January. Alternatively, please contact Crimestoppers on 0800 555 111 where you can give your information anonymously.