Philip gave Queen Elizabeth a gorgeous diamond bracelet on their wedding day -- and Kate loves to borrow it

Queen Elizabeth and Prince Philip marked a milestone this weekend, celebrating 70 years of marriage.

In honor of the special occasion the royal couple posed for new portraits, which were recently released by Buckingham Palace. The portrait shows the two standing side-by-side, the queen in white chiffon with her arms crossed. Philip sports a gray sportcoat and stands just a step behind the queen.

The couple has come a long way since their wedding at Westminster Abbey in November 1947. To this day, Philip's steadfast support of his wife is evident. Perhaps that's the message he sent with the gift he gave Elizabeth on their November 20th wedding day -- a notion of not only love, but a promise to their county.

To mark the start of their marriage, Philip had a large diamond bracelet made from the diamonds shared by Elizabeth's engagement ring. Set in platinum, the Duke reportedly had a large role in the creation of the quatrefoil bracelet with prominent London jeweler Philip Antrobus.

The queen has sported the seven-decade-old bracelet at a number of royal occasions. But even though she's taken a step back from her royal duties, we can still expect to see the stunning piece of ornament at many official functions, as she's been sharing the bracelet with Duchess Kate.

Kate has been seen wearing the bracelet a handful of times, most recently at a gala where she also debuted her new bump. She also sported a pair of diamond chandelier earrings, which were also borrowed from the queen.

According to many reports, the queen boasts one of the most extensive jewelry collections in the world -- and if this bracelet is any indication, the rest of her jewels are absolutely gorgeous.