Even now, 25 years after her death, Diana may still be the alpha influencer. An amethyst and diamond pendant that the Princess of Wales wore repeatedly in the late 1980s — on loan from Naim Attallah, group chief executive of Asprey at the time — was hotly contested at a Sotheby’s London sale in January.

It sold for 163,800 pounds (or $197,453 at the time), potentially the highest price ever realized for jewelry in the shape of a cross, according to Kristian Spofforth, head of jewelry for Sotheby’s London. “As far as I’m aware — and I’ve done some digging — I can’t find one that’s sold for more,” he said.

The winning bidder? Kim Kardashian, who recently has been buying or borrowing items linked to 20th-century style icons. As the face of the Ciao Kim collection from Dolce & Gabbana, a brand steeped in Catholic iconography, she wore a crystal cross choker in one of its spring advertising campaign photographs.

Add to the mix Rihanna’s jewelry choices during her very fashionable first pregnancy — including a 1980s Christian Lacroix cross in the photo reveal — and it is apparent that the motif has more high-profile, high-fashion visibility than any time since the 1990s and early aughts, when women like Drew Barrymore and Cindy Crawford regularly wore crosses.

Is it just a matter of time before everyone is again copying Madonna’s “Like a Virgin” look circa 1984? And is it possible to wear a cross without running afoul of any number of 21st-century sensitivities, including the question of appropriating Christian symbolism?

According to Michael Coan, an associate professor of jewelry design at the Fashion Institute of Technology in New York City, crosses are not an exclusively Christian symbol. “They existed thousands of years before Christianity,” he said. “Crosses have been appropriated heavily by the Christian faith, but it’s not the only one to use them.”

Details matter in this category. “If you have Jesus on it, it becomes a crucifix,” he said. “That’s a different story.”

The multiple potential interpretations of a cross give designers room to “imply that it’s for everyone,” Mr. Coan said. “For some people, it can mean redemption from suffering. To pagans, it can mean the four directions. It can represent elements of fire, water, earth and air. It’s a symbol that resonates on a global plane.”

The rediscovery of crosses also is consistent with changing tastes. “We went very personal with jewelry about 10 to 15 years ago — with nameplates and initials,” he said. “We’re now into charms with life-affirming attributes. Crosses are becoming part of that.”

However, the views of those in different Christian denominations vary.

In a 2018 speech, Pope Francis referred to the crucifix as “not an ornamental object or clothing accessory — sometimes abused — but a religious sign to be contemplated and understood.”

Robert Covolo is the author of the 2020 book “Fashion Theology” and a pastor at the Christ Church Sierra Madre in California, which describes itself as “a gospel-centered church, rooted in historic Christianity.” He said he doesn’t take issue with someone wearing a cross, whether from genuine belief in what he called its “official meaning,” which “represents the passion of the son of God and is also symbolic of God’s great unmerited love for us” or because “they just think it’s cool.”

He referred to the Apostle Paul, who, according to Dr. Covolo, “didn’t care what people’s motives are for sharing about the cross.” In any event, he said, he believes the cross remains a potent emissary for Christianity: “It’s not going to lose its capacity as a religious symbol; it can’t.”

As a style choice, Mr. Spofforth of Sotheby’s observed that crosses are not immune to trend cycles. “Like many, many different pieces of jewelry, they go in and out of fashion,” he said. “But the really good examples will always be popular.”

The Diana pendant, called the Attallah Cross, is a case in point, he said: “It’s a really beautiful piece in its own right; the combination is really lovely, of really deep purple amethysts and diamonds, and the silver work of the front is very striking.”

In addition, the connection to the princess gives it an X factor. “When you add the provenance,” he said, “you really ramp up the interest.”

He advised anyone considering the purchase of a cross to exercise care. “It’s been a very strong symbol, not always in the most positive way,” he said, offering as examples two World War II military medals, the Croix de Guerre of the Vichy government in France and the Iron Cross of the Nazi German government.

“If you’re going to wear a cross, I would choose it carefully to be sure it is one with better connotations rather than one of the nastier ones,” he said.

Theo Fennell, the London designer whose jeweled crosses (starting at $800) have become one of his brand’s signatures, said that when he was beginning his career more than 45 years ago, “it was as much of a peace and love sign — like a dove or a ‘ban the bomb’ sign — as it was a religious symbol.” By the 1980s, it was “by people in the music business, rappers.”

A cross is a form that he said is endlessly inspiring, with lots of surfaces and dimensions to embellish: “It is a wonderful shape to work with because it has so many places where you can put things. There’s so much you can add to it. We’ve made crosses that opened up and had portraits in them, and enamel. I don’t think there’s a jewelry technique we haven’t used in a cross at some stage.”

Preferred styles come and go, he noted. “It was very much stone-set up to the mid-80s, and then we started to do a lot of gothic crosses with predominantly gold in a more Renaissance way,” he said. “Our favorite was always having stones carved into the four arms of a cross and then adding gold to those and whatever detail the client asks for to incorporate their favorite things.”

Loree Rodkin, the Los Angeles jeweler who has made crosses a cornerstone of her brand since founding it nearly 40 years ago, said her clients currently favor bold flourishes. “The demand right now is for much larger statement crosses of great size,” she said. “People are wearing them for the drama.”

The singer Lourdes Leon, a daughter of Madonna’s — who, Ms. Rodkin said, was an early client — wore one of the jeweler’s white gold and diamond crosses to the Grammys in February. She wasn’t alone; Lizzo performed in a Dolce & Gabbana crystal cross pendant from the vintage boutique and rental service Paumé Los Angeles, and Kim Petras, a winner for the song “Unholy,” wore a gold cross around her ankle from the same rental company.

Ms. Rodkin said she has been attracted to crosses by their evocative possibilities. “I think there’s a great romance to all the churches of the world,” she said. “But I never did it as a religious statement. It was more medieval, more Romeo and Juliet.”

She said she always viewed the cross as transcending spiritual affiliation. “I launched my brand with crosses, and I’m Jewish,” she said, noting that even her mother initially expressed a few reservations. “But when I told her Barbra Streisand was buying them, she said, ‘OK, well, I’ll wear one, too.’”

Nancy Badia, founder and co-designer of the jewelry brand Buddha Mama in Miami, offers jeweled and enameled crosses with a boho bent in gold, rings, rosary-style necklaces and pendants (from $3,600 to $100,000), along with designs drawn from Eastern spiritual traditions. And regarding requests for jewelry featuring crosses, she said, “there’s been a resurgence, for sure.”

“I’m a Buddhist, but I like the symbolism of the cross,” she said, noting that she has never received negative feedback for wearing a cross or creating one with a fine-jewelry gloss.

Dakota Badia, Ms. Badia’s daughter and co-designer, said she believes “the cross is seen as acceptable in fashion because it has been used that way for a long time. But, on the other hand, we’ve definitely heard some pushback about our jewelry with the Buddha.”

And while the brand offers some pieces that juxtapose various symbols like the mandala, the hamsa and the evil eye, they do not include the cross. “We don’t mix it with other things,” Ms. Badia said. “In the back of my mind, I have a respect for the symbol and feel like it should be alone.”

A large pendant set with sapphires, tanzanites and aquamarines on a black velvet cord, one of the more striking crosses that Rihanna wore during her first pregnancy is a vintage piece available at Briony Raymond, a jeweler in New York City.

And many clients have commissioned Ms. Raymond to create cross pendants (starting at $3,500), from First Communion gifts to a highly decorated medallion with a cross to commemorate a 75th birthday.

“The confluence of religion and fashion and where people set boundaries,” she said, is a subject that fascinates her. “Some of my clients come in and will look at an exceptionally fine cross and see a really beautiful piece of jewelry, and another will say, ‘This really speaks to my Christian upbringing.’”

She also knows some people buy cross jewelry to adopt Y2K fashion, styles popular at the turn of the millennium. “I’m reticent to compare wearing a cross and a wide-legged jean or a crop top,” she said. “One is so much more deeply entrenched and has meaning for many people. But for other people, that is not the case.”

“I do understand when people who are not particularly religious wear crosses just because they’re beautiful,” Ms. Raymond said. “That’s what’s so interesting about jewelry. It can have such different meanings to different people. We see what we want to see.”