Join the hue: buyers chase the ‘hidden treasure’ alexandrite

When the hammer came down at $1.92mn in December for a ring featuring a 16.53-carat alexandrite and diamonds, the sale set a new auction record for the coloured gemstone. The amount was nearly five times the low end of the presale estimate of $400,000- $600,000.

In the same Sotheby’s auction in New York, a pair of earrings featuring two oval alexandrites — of 7.69 and 7.38 carats — set with diamonds sold for $1.2mn, against an estimate of $200,000- $300,000.

While these jewels were particularly rare examples, the eye-catching results nevertheless reflect the growing interest in what jeweller Sophia Hirsh calls “one of the most fun gems to wear”.

Alexandrite is a rare colour-changing variety of chrysoberyl that was discovered in Russia in 1830.

It is often described as “emerald by day, ruby by night” because of its change in hue from green to bluish green in daylight, to red to purplish red in incandescent light.

Today, the finest-quality examples, which have a prominent colour change, purity of colour and high clarity, tend to originate from Brazil. Another source is Sri Lanka: Phillips is offering a ring set with a Ceylon cushion-shaped, 6.89-carat alexandrite with a colour change from brownish-green to reddish-purple for SFr45,000-SFr62,000 ($50,000-$70,000) in Geneva on May 12.

Top-quality natural alexandrites are difficult to acquire. “When I go on gem-buying trips, we see very, very little material, and the material we do see is almost never above two and a half [or] three carats tops,” says Hirsh, managing director of Hirsh London. “Occasionally, you will have larger examples, [but] generally they’ll be quite included or won’t necessarily have the most dramatic colour change. So to find a large example that has exceptional colour change is like finding a meteorite in your back garden. It’s very rare.”

Hirsh says alexandrite is something of a “hidden treasure”, in part because of the prevalence of mass production in the jewellery industry and advertising by large brands. “A lot of things are pushed that can be repeated and reproduced,” she says. “And, of course, with alexandrites you can’t do that, so there’s not really been much marketing or push by any scale players.”

To find a large example that has exceptional colour change is like finding a meteorite in your back garden. It’s very rare

Even so, there is increasing public knowledge, coinciding with the wider growth in interest in coloured stones generally. “Although it’s lesser known than rubies, emeralds and sapphires, awareness of alexandrites has definitely grown over the years,” says Anna Ruzhnikov, head of high jewellery sales at Sotheby’s in New York. “I would attribute that to social media [and] auction houses raising awareness. There’s also interest among young couples who are looking for an individual engagement ring that’s something a little different; an alternative to a white diamond.”

As a result, she says, private clients are competing against dealers and collectors for alexandrites, which is “really what’s driving the price up”.

Veeraj Haria-Shah proposed to his now wife, Alexandra, with an engagement ring he designed with private jeweller Natalie Landale in 2022. It is set with a central cushion-cut alexandrite from an antique piece, with a Cadillac-cut diamond either side. He hadn’t heard of the stone before Landale showed it to him, but researched its back-story. He knew his partner was “after something that was different”, so the rarity appealed.

“I knew no one else would have it, so it was almost about having a truly unique piece that not everyone would either choose or would want to wear,” he says. “It almost felt like a ring that had two different pieces of jewellery inside of it.”

Haria-Shah, founder of London-based menswear brand Coconut Residence, says the colour change, from “a light moss green” in bright sunshine to a “garnety red” in the evening, “still surprises us to this day”.

Engagement rings account for half of Hirsh London’s designs with alexandrites. The house recently worked on a bespoke platinum piece with a 0.55-carat brilliant-cut alexandrite set with three equally sized round diamonds on either side.

Garrard introduced alexandrite to its Jewelled Vault selection of one-off pieces about five years ago, with recent designs including an 18-carat white gold ring set with a 2.20-carat oval alexandrite and diamonds.

Claire Scott, design and development director at the British jeweller, says its alexandrite pieces have been popular and have “moved very quickly”. She says that while initially the team “wasn’t sure how well clients understood alexandrite”, they have found there is interest, particularly in China, in unusual gemstones.

“For people — even for me — it’s quite magical that it changes colour so much in different lights,” says Scott. “And that obviously from a design perspective gives the piece a different look.”

The change in hue presents a marketing challenge, however. “One of the hardest things actually . . . is capturing it on film [or] in the photograph so you get a true representation of the colour,” says Sara Prentice, creative director at Garrard. She says alexandrite pieces are therefore sold in person when a client can see how the stone reacts to the light, rather than from an image.

Despite the “cool phenomenon” of the colour change, Hirsh says an alexandrite is “never ostentatious”. “You have something that’s not big in terms of the carat weight necessarily but very, very exceptional in terms of its uniqueness,” she says.