Kate Middleton wore a vintage pearl necklace to commemorate Holocaust Memorial Day on Jan. 27, purchased from Jewish-owned brand Susan Caplan

Catherine, Princess of Wales lights a candle during a ceremony commemorating Holocaust Memorial Day on January 27, 2025 in London, England

Catherine, Princess of Wales lights a candle during a ceremony commemorating Holocaust Memorial Day on Jan. 27, 2025 in London, England. Photo: Dan Kitwood/Getty

Kate Middleton’s latest jewelry purchase is as thoughtful as it is chic.

Stepping out on Jan. 27 to attend the Holocaust Memorial Day service in London alongside Prince William, the stylish royal wore a vintage pearl necklace that conveyed a powerful message.

“The fact that she wore a necklace from our collection, being a Jewish brand, I was so touched by that,” Susan Caplan, founder of the eponymous vintage jewelry brand, tells PEOPLE.

“To wear it on a day that for myself and for the whole Jewish community holds such great significance, it felt very special,” she adds.

The five-row graduated faux pearl necklace, which was purchased directly from Caplan’s website, is one of many that the renowned buyer bought a while ago from one of her regular suppliers.

“It has a lovely adjustable clasp so you can wear it higher up or lower down, and the clasp is embellished with some gorgeous little Swarovski crystals,” Caplan explains from her home in London.

Catherine, Princess of Wales talks with Yvonne Bernstein at a ceremony to commemorate Holocaust Memorial Day and the 80th anniversary of the liberation of Auschwitz-Birkenau at Guildhall on January 27, 2025 in London, England

Catherine, Princess of Wales talks with Yvonne Bernstein at a ceremony to commemorate Holocaust Memorial Day and the 80th anniversary of the liberation of Auschwitz-Birkenau at Guildhall on Jan. 27, 2025 in London, England.Arthur Edwards – WPA Pool/Getty

It was at her home on Monday evening that she turned on her TV and unexpectedly spotted Kate wearing the $291 piece of jewelry and instantly recognized it as one from her own collection.

“I switched it on just at the point where she was lighting the candle, and I was just very overcome with emotion,” Caplan says. “It touched my soul that she did that, and it was clearly a very noticeable, standout piece of jewelry.”

Kate often discreetly nods to an occasion with her style choices, much like the late Queen Elizabeth did, wearing colors and emblems that nodded to a host country on tour, for example, and on other occasions. The symbolism is more discreet, but nevertheless just as impactful.

“I think there’s an emotional attachment when it comes to jewelry, and Catherine always gets it right,” says Caplan, 68, who founded her brand in 2008. “She’s so sensitive and I think she’s able to convey just the right message with the right outfit or the right piece of jewelry for the right occasion, and I think that’s because she is so sensitive.”

It’s a quality that reminds Caplan, whose clients include Beyonce and Adele, of William’s late mother Princess Diana, someone who combined her style and elegance with kindness and humanity.

“To me, she is another Princess Diana,” Caplan says. “She had so much style and wore everything so well, just like Catherine. And she is just so natural, so gorgeous and genuine. She was caring, loving and sensitive — you don’t learn that, it’s deep inside of you.”

While Caplan is working her magic to get more necklaces in stock soon, it’s unlikely she will be able to meet the demand from customers who have e-mailed her around the clock since the afternoon of Jan. 27, the same day Kate wore her piece.

“We only have a few more which are currently being shipped to me, so that’s why they are out of stock,” Caplan says. “We have had many, many calls!”

It was a poignant moment in time that the jewelry curator says she will treasure forever: “I do think Kate chose this because she wanted to support a Jewish brand at this particular time,” she says. “They did their research, and I felt very honored that she would go to a Jewish brand.”