An unusual Ceylonese sapphire ring was stolen during a burglary.
The ring, from the island now familiarly known as Sri Lanka, was stolen from a house in South Drive, Ferring, near Worthing, on Saturday.
The thief or thieves got in through an insecure door and also stole a quantity of cash.
Katy Wood, an investigator with the priority crime Team in Bognor, said: "The ring in particular is of great sentimental value to the owners and is a sad loss to them.
"I would ask anyone who may have seen or heard anything suspicious, or who has other information about this incident or the stolen property, to contact us.
"Police would urge all householders to double check that doors and windows are locked before going out or retiring to bed."
Anyone with information should email 101@sussex.pnn.police.uk or phone101, quoting serial 411 of 4/4. Alternatively they can contact the independent charity Crimestoppers without having to leave their name on 0800 555 111.
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