Diamonds

Who Invented the Princess Cut Diamond? Meet Bez Ambar

Bez Ambar · October 17, 2014

The Princess Cut is the second most popular diamond shape in the world. It is in millions of engagement rings, wedding bands, and fine jewelry pieces across every price point. The person who invented it works in Downtown Los Angeles. His name is Bez Ambar.

The Problem in 1979

Why Someone Needed to Invent a New Cut

The modern diamond industry in the late 1970s had a dominant shape: the round brilliant. Tolkowsky’s 1919 calculation of ideal proportions for a round diamond had been refined over sixty years into a cut so well-optimized that it became the default. If you were buying a diamond, you were almost certainly buying a round.

Square diamonds existed, the old mine cut, the emerald cut, the baguette, but none of them performed like a round brilliant. The stepped cuts produced dramatic flashes but not brilliance. The old square cuts had inconsistent faceting that left them looking dull by comparison.

Bez Ambar, then a young diamond cutter working in Los Angeles, saw the problem clearly: there was no square brilliant diamond. No square cut that matched the light performance of a round. He decided to create one.

The Development

From 1976 to 1979, Bez worked on a facet arrangement that would do for a square what Tolkowsky’s proportions had done for a round: create a systematic geometry that maximized brilliance, fire, and scintillation from a square girdle.

The challenge was the corners. A round diamond has no corners, the girdle is continuous, and light reflects symmetrically in every direction. A square diamond has four sharp corners where the geometry changes abruptly. Managing how light behaves at those corners, and how the pavilion facets adjacent to them direct light back through the table, was the core technical problem.

Bez solved it with a 49-facet arrangement, crown and pavilion facets positioned to maintain high light return across the entire face of the stone, including the corners. The result was a diamond that was as brilliant as a round brilliant but distinctly square. He named it the Quadrillion Cut™.

The Award

De Beers Recognized It

The De Beers Diamond Award, the most prestigious recognition in the diamond industry, was given to Bez Ambar for the Quadrillion Cut. De Beers, at the time the world’s dominant diamond mining and marketing company, awarded the prize to innovations that materially advanced the art of diamond cutting.

Receiving the award confirmed what Bez had accomplished: not a variation on an existing cut, but a genuine invention. A new solution to a problem the industry had not previously solved.

The Name Change

From Quadrillion to Princess

Bez sold the cutting rights to the Quadrillion Cut to Lex Polished Diamonds in the early 1980s. Lex licensed the cut to manufacturers globally and rebranded it for the retail market.

The new name was the Princess Cut. Softer, more romantic, easier for a consumer to remember than “Quadrillion.” Lex was right about the marketing, the Princess Cut grew into the second most popular diamond shape in the United States within a decade, and it has held that position for over forty years.

The name changed. The cut did not. Every Princess Cut diamond sold anywhere in the world today, from a $300 solitaire to a six-figure custom piece, is cut to the geometry Bez Ambar developed in his Los Angeles studio in 1979.

After the Invention

What Bez Built Next

Bez did not stop at the Quadrillion. After establishing himself as the inventor of the world’s most successful new diamond cut, he continued developing new cuts and setting methods through the 1980s and 1990s.

The Blaze® came later, a cut optimized not for brilliance but for fire, producing color dispersion roughly ten times higher than a standard round brilliant. The Blaze® is used throughout the Bez Ambar collection, typically as a shank treatment or in halos where the color fire frames a different center stone.

The Bez Ambar studio in Downtown Los Angeles continues to manufacture to this day, custom engagement rings, wedding bands, and fine jewelry pieces all produced in the same building where the Quadrillion Cut was invented.

Frequently Asked Questions

Who invented the Princess Cut diamond? Bez Ambar invented the square brilliant diamond, originally named the Quadrillion Cut™, in 1979. De Beers recognized the invention with its Diamond Award, the most prestigious honor in the diamond industry. The name “Princess Cut” was introduced when Lex Polished Diamonds licensed the cut from Bez and rebranded it for retail sales.

Is the Quadrillion Cut the same as the Princess Cut? Yes. They are the same 49-facet square brilliant cut. Quadrillion Cut™ is Bez Ambar’s original name. Princess Cut is the trade name that became universally adopted after Lex Polished Diamonds licensed the cut in the early 1980s.

Did Bez Ambar win an award for inventing the Princess Cut? Yes. De Beers, then the most powerful institution in the diamond industry, awarded Bez the De Beers Diamond Award for the Quadrillion Cut. The award recognized genuine advances in diamond cutting technique.

Does Bez Ambar still sell Princess Cut diamonds? Yes. Bez continues to cut Quadrillion diamonds at his Downtown Los Angeles studio to the original specifications. These are not commodity princess cuts from wholesale supply, they are cut in-house to the proportions Bez developed in 1979. Contact the studio for current inventory and custom work.

What other diamond cuts did Bez Ambar develop? After the Quadrillion, Bez developed the Blaze® Cut, a proprietary faceting pattern that maximizes fire (color dispersion) rather than white light brilliance. The Blaze® is a registered trademark and is used extensively throughout the Bez Ambar collection as a design element in shanks, halos, and standalone pieces.

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