A bride-to-be is desperate to find a lost engagement ring which belonged to her fiancé's late mum.

Joannah Wyx, from Canterbury, believes the unique piece of avant-garde silver jewellery with eight diamonds slipped off her finger at Sainsbury's in Kingsmead on Friday afternoon.

The 48-year-old had worn the ring, originally given to her partner Jeremy's mother Sylvia by his father in the 1950s, for the last six years.

But she fears that its unusual design, having been made bespoke for Sylvia and then left to Jeremy when she passed away in 2012, means that the person who stumbled across it might not realise its true value.

"We are concerned that someone has picked it up thinking it is only a dress ring, because of its unique design. They may have even given it to their daughter to play with," she said.

Ms Wyx, who uses a wheelchair, realised her left hand was bare when she and her fiancé got back to their car after finishing their shopping between 3.45 and 5.30pm.

"I got in the car and put my left hand on the steering ball, and thought 'oh my god, my ring'," she continued.

"I'm still in shock about it. However much we look, and go through everything, we just can't find it.

"Our ring is irreplaceable. Jeremy's late father Bernard bought the ring for his betrothed in approx 1954, when Sylvia was 18 and he was only 20.

"We are both heartbroken, but hopeful that a kind person will hand it in to someone."

The couple are now offering a reward to anyone who can reunite them with the cherished family heirloom.

"I can't put into words how happy I would be if someone were to find it. I would be more than overjoyed," she said.