Charlotte said: “When Prince Charles got down on one knee and asked Camilla to marry him in 2005, he did so with a clean, contemporary, magnificent diamond engagement ring.
“More reminiscent of the geometric bold lines favoured by today’s young fashionistas, in contrast to, for example, the classic and opulent oval and diamond halo of Princess Diana’s sapphire ring, it was passed down to him from the Queen Mother, who was first pictured wearing it in the 1980s.
“Although the royal household has never divulged its date of creation or why it was commissioned, they have called it a family heirloom, implying a certain depth of history.
“Some speculate that the ring was in fact made to celebrate Queen Elizabeth II’s birth in 1926.
source: express.co.uk