Kate Middleton and Princess Diana in the emerald and diamond choker.Photo: Karwai Tang/WireImage; Anwar Hussein/Getty

Anwar Hussein/Getty

Kate Middletonwore the ultimate accessory to theEarthshot Prize Awards ceremony on Friday:Princess Diana’s emerald and diamond choker.

The stunning piece hasn’t been seen since Diana herself wore it. It was a favorite of hers; not only did she wear it as a necklace many times between1981and1997, she also famously wore it as a headband in 1985 during her tour of Australia alongsidePrince Charles.

For more on Kate Middleton, listen below to our daily podcast PEOPLE Every Day.

Princess Diana and Prince Charles in 1985.Anwar Hussein/Getty

MELBOURNE, AUSTRALIA - OCTOBER 31: Prince Charles, Prince of Wales and Diana, Princess of Wales, wearing a green satin evening dress designed by David and Elizabeth Emanuel and an emerald necklace as a headband, dance together during a gala dinner dance at the Southern Cross Hotel on October 31, 1985 in Melbourne, Australia. (Photo by Anwar Hussein/Getty Images)

Like Diana did before her, Kate paired the choker with a bright green dress. In keeping with the sustainable fashion theme guidelines for the Earthshot Prize Awards, Kate rented the off-the-shoulder Space London gown from HURR, a rental platform in the U.K. for designer dresses.

Kate Middleton.Karwai Tang/WireImage

BOSTON, MASSACHUSETTS - DECEMBER 02: Catherine, Princess of Wales attends The Earthshot Prize 2022 at MGM Music Hall at Fenway on December 02, 2022 in Boston, Massachusetts. (Photo by Karwai Tang/WireImage)

Kate and William capped off their three-day visit to Boston on Friday at the environmental awards show. William created the Earthshot Prize in 2020 in an effort to combat climate change.

Princess Diana in 1993.

LONDON, UNITED KINGDOM - NOVEMBER 11: Princess Diana Wearing A Dress Designed By Fashion Designer Catherine Walker To A Banquet At The Dorchester Hotel For The Yang Di-pertuan Agong Of Malaysia. (Photo by Tim Graham Photo Library via Getty Images)

Can’t get enough ofPEOPLE’s Royals coverage?Sign up for our free Royals newsletterto get the latest updates onKate Middleton,Meghan Markleand more!

The Prince of Wales refers to the Earthshot Prize Awards — which he created in 2020 — as his attempt to provide some urgent optimism about tackling environmental issues and climate change. He and Princess Kate are “excited to be able to bring that to the United States and inspire people stateside and around the world through the incredible stories we are going to tell,” a source close to the coupletells PEOPLE.

source: people.com