The front of the pendant features a red and white Tudor rose motif intertwined with a pomegranate bush, the symbols of Henry and Katherine.
The back features the letters H and K – for Henry and Katherine – in Lombardic script, linked by ribbon, and the legend + TOVS + IORS.
Experts have dated the pendant to the early 16th century AD, with a most likely date of 1521 during his marriage to Catherine (married 1509 until their annulment in 1533).
It is believed that the jewellery was a prize given to people who participate in an event.
“Nothing of this size and importance from the Renaissance period had been found in Britain for more than 25 years,” said Rachel King, curator of Renaissance Europe at the British Museum.
Duncan Wilson, Chief Executive at Historic England said: “This beautiful pendant is a thrilling discovery giving us a tangible connection to Henry VIII and Katherine of Aragon and enriches our understanding of the Royal Court at the time.”