A metal detectorist has unearthed a medieval gold reliquary cross, potentially worth more than £20,000, while searching a farmer's field.

Shelley Couzins, 58, made the discovery in August after five hours of finding only discarded items. Her detector signaled a find, leading her to uncover the cross about a foot below the surface of a ploughed field on the Isle of Sheppey, Kent. Couzins, a grandmother of five, initially believed the find might be costume jewelry.

"It is like a metal detectorist's dream. You only find something like this once in a lifetime," Couzins stated. She was participating in an outing with the Medway History Finders when she made the discovery.

The 10.6-gram cross features a depiction of Jesus's crucifixion on one side and Mary with the baby Jesus on the other. It has a pin that allows it to be opened, which usually reveals a spiritual object inside, but Couzins refrained from opening it to avoid potential damage. A pearl is present at the bottom, and Couzins believes the cross may have originally had three pearls.

The cross has been classified as treasure and is now being held by the British Museum. If the museum decides to acquire the artifact, its value will be determined and then split between Couzins and the landowner. Couzins, who has been metal detecting for four years, expressed a desire for the cross to go to a suitable historical home.

"I was really excited but at the same time a little bit underwhelmed, because I knew that I would have to hand it in," she said. "I was absolutely gutted because I like to keep everything I find. I know I will probably never see it again."

The cross has been identified as a medieval gold reliquary cross, with a depiction of Jesus's crucifixion on one side and Mary with the baby Jesus on the other

The Isle of Sheppey has historical connections to Henry VIII and the Boleyn family, leading Couzins to hope the cross may be linked to them. She noted the rarity of finding such a complete item, as ploughing often damages or breaks such artifacts.

Couzins's previous finds include a third of a Guinea gold coin from 1822 and a medieval silver bead ring, both of which were also handed in for analysis.