A Personal Note
Every now and then, a jeweler sends out a photo that stops you mid-scroll. Not because it’s big or flashy, but because you know what it took to make it. I’ve always had a fascination with invisible-set jewelry. At nearly every auction we review for the Report, if there’s a worthy invisible-set piece, we’ll point it out.
We all admire how stunning these jewels look — but few talk about what it takes to build them: how the stones are cut to wrap around a curve, how every table must line up perfectly to get that paved, seamless look. No metal showing. No prongs. Just a sheet of color — sapphires, rubies, emeralds, diamonds.
That’s the world of the invisible-set, and nobody has done it longer, more beautifully, or more precisely, than Oscar Heyman.
in a captivating pair of earrings, a modern, flexible bracelet, and a magnificent ring.
The ring alone features 88 square rubies, each individually cut for its unique home
surrounding a 4-carat F/VS2 round brilliant cut diamond.
An Exclusive Roskin Gem News Report
By Gary Roskin
This story started, as many do here, with a simple email. Oscar Heyman’s bi-weekly update — Fresh from the Workshop — usually shows a few new pieces, a pleasure to look through between deadlines. But this time, one line stood out: “Spotlight: Invisible-Set Styles.”
So we called Tom Heyman, great-nephew of Oscar and one of the current stewards of the family firm, to find out how invisible-set jewelry really works — and why so few shops still attempt it.
Stones are individually cut, often re-cut for precision, and arranged;
the result is a seamless mosaic with sculptural and dimensional appeal.
Here, a 5.15-carat round brilliant cut VS1 diamond is encircled by 110 square invisibly set sapphires.
Paris, Patents, and a Handshake
“I’ve always said Van Cleef & Arpels invented invisible-set,” Tom begins. “But Chaumet actually had a 1904 patent. Cartier and Van Cleef both filed in 1933.”
That already changes the story we’ve all told for years. Invisible-set wasn’t one invention — it was an arms race among the great Paris houses.
Oscar Heyman entered the picture in the 1930s. “We’ve always been technically oriented,” Tom says. “Early on we had a machine shop and a few patents of our own — block bracelets, for example. We saw VCA’s invisible-set work and figured out how to make it.”
The result was a handshake partnership that lasted roughly sixty years. “The understanding was simple,” he explains. “We’d make invisible-set jewelry exclusively for Van Cleef; and they’d buy everything we could produce. Every piece engraved VCANY with a five-digit number — that was us.”
Pre-war, Oscar himself traveled to Paris twice a year by boat, spending weeks meeting gem dealers and clients. “He already knew Cartier — he’d worked there around 1908, before our firm even existed — and he got to know Van Cleef. Invisible-set was new, exotic, cutting-edge. New York wanted it, but the Paris workshops were backed up for months. We could supply the demand.”
It was a relationship built on trust. “Claude Arpels’ son even worked with us for about a year around 1990,” Tom recalls. “It was cooperative — we’d speed up or slow down production together. It lasted until management changed at Van Cleef and they moved invisible-set work back to Paris. They asked us to finish what was on the benches and pause new orders. That handshake carried us for decades.”
Deep technical mastery is required to create the signature setting.
Rails, Not Wires
If you’ve ever wondered how these pieces hold together, forget the idea of thin wires. “We don’t use wires,” Tom says. “We die-strike rails — we call them tracks.”
He describes them like tiny T-beams: a flat top with a single leg dropping down. Two rails sit a few millimeters apart, and each grooved stone slides onto both tracks.
The key is how those rails are made. “We die-strike them in the tool room,” he explains. “No casting. Die-striking compresses the metal, no porosity, and gives finer tolerances. Casting means cleanup, and cleanup introduces inconsistencies. Invisible-set tolerances are unforgiving.”
For rings, each track has a support structure underneath, and the stones themselves aren’t perfect squares. “Each row gets slightly wider, making each stone a tiny trapezoid. It gives a softer, more fluid surface — not the graph-paper look.”
Bracelets take it further. “Every link flexes in four directions,” Tom says. “Each rail is one stone long. We actually die-strike a little cube with the rail ridge and connection holes in one piece of platinum — one of our patents covers how to do that.”
We all know about the rails, the notched stones, the way each one slides neatly into place to create that seamless surface. But this — each stone able to flex in four directions, with its own one-stone rail — that is pure genius. The engineering here borders on unreal. The precision is invisible, literally, and it’s what lets the bracelet move like fabric while still reading as a solid sheet of gems.
After the ring has been handcrafted, the lapidary work begins.
Each ruby will require approximately one and a half to two plus hours to be set into its home in the ring.
When Something Goes Wrong
Invisible-set jewelry is strong when worn with care. But repairs? That’s another story.
“If a client chips a stone, it comes back to us,” Tom says. “Our cutter recuts or replaces it. Sometimes you have to slide out several stones to reach the damaged one. On a ring, you might even have to remove a center diamond first.”
Because of how the stones interlock, each one has to move in sequence — there’s no popping one out. “You can sometimes press a stone in at a slightly wider point on the track and slide it into place,” he says, “but it’s delicate work.”
Few U.S. jewelers will even attempt invisible-set repairs today. “They don’t have the tooling or the workflow,” Tom admits. “We don’t repair other makers’ invisible-set pieces either. It’s too specialized.”
before trimming and grooving and paired with over 5 carats of marquise, round, and baguette diamonds.
Sourcing and Cutting
Finding stones that can survive grooving — and still match — is half the battle.
“For bracelets with very precise squares, we buy from a couple of partners we’ve worked with for about fifty years,” he says. “These aren’t standard calibrés. From the girdle down, they’re cut differently so there’s enough material left to groove.”
Heyman orders them in tight size runs — 3.2 × 3.2 mm, 3.2 × 3.3 mm, and so on — then matches tables and cuts grooves.
“For rings, we’ll order a range in tenths of a millimeter. Our cutter fits each stone individually — shape first, groove second. There’s constant back-and-forth with the jeweler. Figure an hour and a half to two hours per stone.”
Matching diamonds to colored stones adds another layer. “We’ve done it two ways,” Tom says. “One used tiny platinum prongs to hold cut-corner square diamonds beside invisible-set colored stones, so the look reads seamless. We’ve also worked with an Israeli cutter who grooves diamonds. Twenty-five years ago that wasn’t possible — lasers changed everything.”
Each stone’s pavilion has to be heavier than a standard calibré to accommodate the groove. “There’s a sweet spot,” Tom says. “Too thin, and it chips; too thick, and it goes dark.”
30 round diamonds and 2 cut corner square diamonds,
these exquisite earrings pair classic flower studs with invisible set drops.
Pieces That Still Amaze
Even after decades, some builds stand out. “We have one we call the Mondrian,” he says. “Blocks of ruby, sapphire, yellow sapphire, and diamond arranged in a grid — inspired by his palette. We first made it about twenty years ago. We’re making another now.”
The trick, he explains, is keeping it from looking mechanical. “It’s easy to make it look like graph paper. You have to balance the color fields and proportion so it feels alive.”
The toughest project was a four-row necklace. “Same block structure as the bracelet, but a necklace curves. The inner rows are smaller, the outer larger, and the front blocks become trapezoids — different shapes inside versus outside. It still has to read as one flat, continuous surface.”
They spent about six months prototyping the dies and angles, another nine months on the build. “Probably fifteen months total,” Tom says. “We aimed for sixteen and a half inches finished. When it was done, it moved perfectly.”
He smiles. “That’s what invisible-set is — engineering that disappears.”
Endurance and Evolution
A century after its founding, Oscar Heyman is still making invisible-set jewelry the same way. “You can’t shortcut it,” Tom says. “Every rail is die-struck. Every stone is fit by hand. A complicated piece can take a year.”
Invisible-set isn’t just a style — it’s a discipline. “You think like a machinist and a jeweler at the same time,” he says. “The precision of an engineer, the eye of a designer.”
That mindset — patient, exacting, quietly confident — has kept this small American workshop producing jewels recognized around the world as defining the ultimate in high jewelry.
Value: The Whole, Not the Parts
A gemologist might look at grooved stones and wince. “You’ve ruined the resale value,” some say. Tom doesn’t disagree. “If you dismantle an invisible-set piece, the stones don’t have much value loose,” he says. “But jewelry isn’t a bag of parts. With invisible-set, the sum is greater than the pieces by design.”
He’s seen buyers approach these jewels the wrong way — calculating what they’d bring if scrapped. “That’s not the point,” Tom says. “These are collector’s pieces. They’re built for people who love precision and beauty working together.”
The setting is crafted from die-struck components.
Each individual square shown in this image is die-struck many times
and formed from a solid piece of platinum before being assembled into a necklace.
The superlative engineering allows for flexibility reminiscent of a silk ribbon.
The View Through the Loupe
Invisible-set jewelry doesn’t shout. It’s quiet perfection — color, light, and geometry, magically locked into harmony.
And maybe that’s why it still fascinates gem enthusiasts. Beneath the smooth surface of perfectly matched emeralds, rubies, sapphires, and diamonds lies engineering at its most meticulous — rails, grooves, cubes, tolerances measured in thousandths.
It’s jewelry built not to be seen, but to be admired.
In the words of Tom Heyman: “It’s not magic. It’s just a lot of careful work.”
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