Scott Sucher and the Hortensia: French Crown Jewel Replica Cut in “Grown Diamond”

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For centuries, the famous Hortensia Diamond has existed as an historical object behind museum glass at the Louvre — a softly colored pink diamond tied to French royal history, Napoleon, thefts, political upheaval, and the long legacy of Europe’s crown jewels.

Often described as “peach colored,” the Hortensia is believed to have been named after Hortense de Beauharnais (1783–1837), Queen of Holland, daughter of Empress Joséphine, wife of Louis Bonaparte – King of Holland, and mother of Napoleon III.

Today, the diamond resides in the Galerie d’Apollon at the Louvre, among the French Crown Jewels collection assembled over centuries by French royalty, including King Louis XIV, who also acquired the famous Tavernier Blue/French Blue diamond later recut into the Hope Diamond.

Now, for the very first time, a full-size replica of the Hortensia has been recreated in actual diamond material using synthetic grown diamond rough, advanced modeling, modern diamond cutting analysis, HPHT treatment, and carefully controlled post-growth colorization.

And according to Scott Sucher, getting close to the original stone’s historic 20.53-carat weight may have been one of the hardest parts.

“We finished at 20.31 carats,” Sucher told the Roskin Gem News Report. “When you’re dealing with a stone this size, removing even the merest whisper of material changes the weight.”

That explanation led Sucher into what he calls the “law of squares and cubes.”

“If I reduce the size of a stone by half in all dimensions, the weight becomes one eighth,” he explained. “So even at full size, if you remove fractions of a millimeter, the weight changes dramatically.”

In other words, recreating an historic diamond is not simply about matching shape. It is also about balancing optics, dimensions, symmetry — or in this case, intentional asymmetry — and hoping you get close to the historic weight.

And that is where this project becomes far more interesting than simply producing a colored synthetic diamond.

“We’re not just trying to make a pink diamond,” Sucher said. “We’re trying to recreate the appearance of a very specific historic pink diamond.”

That distinction matters.

Modern synthetic grown diamond production can create colored diamonds relatively routinely today. But matching the exact visual personality of an historic stone — including hue, tone, saturation, facet reflections, and optical behavior — becomes a very different challenge.

Especially when the original diamond itself was cut centuries ago.

The Hortensia is not a modern brilliant cut designed for maximum light return. Its facet arrangement, asymmetry, outline, and proportions reflect historical cutting methods rather than modern optimization.

That meant the cutting team had to intentionally avoid some of the instincts modern diamond cutters spend their careers mastering.

“Modern cutters are usually trying to maximize brilliance and preserve weight,” Sucher explained. “Here, we’re reproducing history.”

Sucher provided not only the historical measurements and facet arrangement, but also a highly detailed digital cut model of the original stone using DiamCalc, the advanced diamond modeling and optical analysis software developed by OctoNus.

Cutting an Historic Replica

For most readers outside the advanced cutting and appraisal world, DiamCalc is one of the trade’s major diamond simulation programs — used to model how a diamond handles light before the stone is ever cut.

The software allows cutters and researchers to build a virtual diamond with exact proportions, facet angles, symmetry, girdle outline, and depth relationships. From there, the program can simulate brightness, contrast, scintillation, light return, leakage, and overall appearance under different lighting conditions.

In modern manufacturing, programs like DiamCalc are often used to help maximize brilliance and optimize yield from rough.

But in this case, the software was being used for something very different: recreating a centuries-old historical cut whose proportions were never intended to follow modern cutting standards.

“I provide the cutting instructions and the DiamCalc model,” Sucher explained. “That allows the cutters to analyze the sequence and figure out how to translate my information into real-world diamond cutting.”

Growing Rough

The project used a 42-carat piece of CVD-grown rough.

Interestingly, Sucher says the actual growing process may now be one of the easier parts of the operation.

“Apparently, the growing part is the easy part now,” he laughed.

The larger challenge came afterward.

The replica first had to be cut to roughly 80% completion before undergoing HPHT treatment at approximately 1900 degrees centigrade and roughly 750,000 PSI.

That process intentionally creates crystal dislocations and vacancies needed for later colorization.

And yes — there was always risk involved.

“It could shatter during HPHT,” Sucher admitted. “That was one of the few parts we didn’t fully control.”

After treatment, the stone was then finished to final dimensions before undergoing carefully calibrated electron bombardment to produce the final pink coloration.

That sequence was critical.

According to Sucher, the final facet arrangement itself affects how color appears inside the stone.

“You need the final cut completed so you can analyze all the optical properties — brilliance, contrast, head shadow, everything,” he explained. “Then they can dial in the recipe for the electron bombardment.”

And that recipe involved much more than simply “making it pink.”

“We had extensive conversations about saturation, hue, tone — all of it,” Sucher said. “The eye can discern millions of colors. It’s a delicate operation.”

The project also required careful material selection from the beginning.

Sucher explained that the team ultimately selected CVD-grown material because it was better suited to the demanding sequence of cutting, HPHT treatment for intentional crystal dislocations, and later colorization required for the project.

The final result may represent something museums and historical collections have rarely had available before: a historically accurate replica that actually behaves optically like diamond.

No Longer CZ or Glass

For decades, museum replicas of famous diamonds have generally been produced in glass or cubic zirconia.

But while those replicas may reproduce size and shape reasonably well, they do not reproduce diamond optics.

The brilliance is different.

The scintillation is different.

The dispersion is different.

Even the overall “life” of the stone changes under light.

“What we’re trying to do is historical reconstruction,” Sucher said.

And for museums, that distinction matters.

Instead of displaying replicas that merely imitate shape, institutions may eventually have the ability to display reproductions that behave visually like the originals themselves.

The Hortensia project also builds upon earlier half-scale experiments recreating other famous diamonds, including the Dresden Green and the Wittelsbach.

Those earlier projects helped establish what Sucher jokingly described as a “Rosetta Stone translation” between historical gemstone modeling and modern diamond cutting workflows.

Once that process became workable, the team moved toward a full-size recreation.

Why the Hortensia?

Sucher says the stone simply checked all the boxes.

“It’s fairly well known. It’s gorgeous. The scintillation is amazing. There’s cultural identity attached to it. It has uniqueness.”

For now, the original Hortensia remains safely housed at the Louvre.

But its modern twin — recreated through a combination of historical research, modern cutting technology, synthetic diamond growth, advanced treatment methods, and a surprising amount of patience — may represent the beginning of an entirely new category of gemological historical reconstruction.

And remarkably, the project may still only be getting started.

Sucher says future recreations could move into even larger historic diamonds — potentially in the 40-to-60-carat range.

“Now that we know we can do this,” he said, “the possibilities get very interesting.”

For more about the historic Hortensia Diamond, tap here to access
Grant Mobley’s feature, “The Hortensia Diamond: The Pink French Crown Jewel That Survived Revolution and Theft,”
in Only Natural Diamonds.