However, in the British Royal Family, Fergie’s ring is the most inexpensive, according to Ms Beatson.
When asked about the ring in Sarah and Andrew’s first official interview as a couple, Fergie described it as “stunning” and “red”.
The Duchess of York’s engagement ring is one of the most recognisable royal jewels, as it features a huge Burmese ruby surrounded by 10 glittering diamonds.
The stones form a flower pattern which is also known as a cluster ring.