A bespoke necklace and engagement ring were among gems stolen in a raid.
It was taken from a home in Southbourne Avenue, Southbourne, near Chichester, between January 31 and February 2 while the owners were away.
A Sussex Police statement said: “The bespoke item is a necklace made specifically for the owner as a sentimental gift.
“The necklace is described as a yellow gold chain with an uncut unpolished emerald stone set in a yellow gold setting. The item is very unusual and really is one of a kind.”
Detective Constable Della Squires said; "Were you in the area around the relevant time and if so did you see anything unusual or anyone acting oddly?”
Call Sussex Police on 101.