The Spencer girls’ pearls

DIANA’S favourite style was the pearl choker, the first of which she received as an 18th birthday gift from her family — a pretty triple- strand design with a flower cluster clasp.

Originally, the clasp had turquoise stones in it as well as pearls, and she would wear it to the front only when it matched her outfit — and to the back when it did not.

In photographs taken aboard the Royal Yacht Britannia while she and Charles were on honeymoon in 1981, the stones can be seen shimmering at the front of the necklace, coordinating with her floral Donald Campbell dress.

Around 1984, Diana opted to have the turquoise stones replaced with pearls, meaning she never had to hide the clasp at the back.

Here, in a straw boater at Ascot in June 1981, she paired it with a Benny Ong peach crepe suit and a cream blouse with a trademark ruffle neck, also by Ong. The revamped necklace was spotted offsetting a pink suit and hat during a walkabout in Tetbury in May 1985, and again with a pair of pearl pendant earrings at an evening function in America that November.

Her two older sisters, Jane (above right) and Sarah, both received the same necklace to mark their 18th birthdays. The piece was most likely made by Collingwood of Conduit Street, Mayfair, the Spencer family jeweller. The siblings continued to wear the necklace for several years.

At Diana’s funeral in 1997, all the Spencer ladies — including her mother, Frances Shand Kydd — wore strings of pearls in her honour.