Diamonds
Quadrillion Cut vs Princess Cut: What Is the Difference?
The Quadrillion Cut and the Princess Cut are the same stone. They share the same geometry, the same facet arrangement, the same optical properties. The difference is history, and who invented it.
The Origin
Bez Ambar Invented the Square Brilliant Diamond
In 1979, Bez Ambar, then a young diamond cutter working in Los Angeles, developed a new way to cut a square diamond that maximized brilliance in a way no previous square cut had achieved. The round brilliant had dominated fine jewelry for decades; Bez set out to match its fire in a square format.
The result was the Quadrillion Cut™. It took years of development. The facet arrangement, 49 facets cut to precise angular specifications, was designed to produce the same kind of light performance that makes round diamonds so compelling: internal reflection, dispersion, and brightness working together rather than in competition with one another.
De Beers, at the time the most powerful force in the diamond industry, recognized the Quadrillion Cut with its Diamond Award, the most prestigious honor in the field. That award confirmed what Bez already knew: this was a genuinely new achievement in diamond cutting, not an iteration.
The Name Change
Where “Princess Cut” Came From
Bez sold the cutting rights to the Quadrillion Cut to Lex Polished Diamonds in the early 1980s. Lex licensed the cut to other manufacturers and began marketing it under a new name: the Princess Cut.
The name took. “Princess” was softer, more romantic, easier for retail jewelers to sell. By the mid-1980s, the Princess Cut was the second most popular diamond shape in the United States, behind only the round brilliant. It remains there today, accounting for roughly 25 to 30 percent of all diamond jewelry sales.
The Quadrillion Cut™ is the original. The Princess Cut is what everyone calls it now. Bez Ambar is the person who invented it.
What Makes It Different From Other Square Cuts
The Quadrillion Cut vs Asscher, Radiant, and Cushion
Square diamonds existed before the Quadrillion. The distinction matters because each cuts light differently.
Asscher Cut: A stepped cut developed in 1902. It produces long, parallel flashes of light, dramatic and architectural but not brilliant in the technical sense. The optical effect is deep, hall-of-mirrors reflection rather than sparkle.
Cushion Cut: A square or rectangular shape with rounded corners and a large facet pattern. It produces a soft, pillow-like sparkle. Predates the brilliant era; modern cushion cuts vary widely in faceting and quality.
Radiant Cut: Introduced in 1977, also aimed at producing brilliance in a square format. It has trimmed corners, where the Quadrillion/Princess has sharp corners. The corner geometry changes how the diamond looks in a setting.
Quadrillion/Princess Cut: Sharp corners, the defining physical feature. The facets narrow toward those corners, creating a pavilion that reflects light differently than any of the above. Under the right conditions, the corner facets produce a distinctive optical signature: a bow-tie-shaped light pattern visible when you look directly down the table. Well-cut princess/quadrillion diamonds minimize this effect while maximizing the overall brightness of the stone.
Buying a Quadrillion or Princess Cut
What to Actually Evaluate
Cut quality in princess/quadrillion diamonds is harder to assess than in rounds because GIA grades them as Excellent/Very Good/Good without a standardized cut grade equivalent to the round brilliant. A princess cut graded Excellent for polish and symmetry can still be poorly proportioned.
The proportions that matter most:
Table percentage: The flat top facet as a proportion of the total girdle diameter. Between 62 and 72 percent is the accepted range for well-cut stones. Below that, the stone looks deep and dark. Above that, it loses brilliance in the crown.
Depth percentage: Total depth from table to culet as a proportion of diameter. 64 to 75 percent is the target range. Stones cut too shallow or too deep sacrifice light return.
Length-to-width ratio: True squares are 1.00 to 1.05. Anything beyond 1.10 starts to look rectangular, which is fine if that is the intended shape.
The bow-tie: Hold the stone face-up under direct light. A well-cut stone shows high brightness across the entire table. Dark areas at the center or at the corners indicate poor proportioning.
Bez Ambar’s Quadrillion Today
Still Cut in Los Angeles
Bez continues to cut Quadrillion diamonds in the Downtown Los Angeles studio where the cut was invented. Every Bez Ambar piece set with a square diamond uses the original Quadrillion proportions, not a generic princess cut sourced from a commodity cutter.
The difference is measurable: stones cut to the original Quadrillion specifications consistently return more light than mass-market princess cuts because the facet angles are set to Bez’s original design, not to maximize yield from the rough.
Frequently Asked Questions
Is the Princess Cut the same as the Quadrillion Cut? Yes, they are the same facet pattern. The Quadrillion Cut™ is Bez Ambar’s original 1979 name for the square brilliant diamond he invented. The trade adopted “Princess Cut” in the early 1980s when Lex Polished Diamonds licensed the cut and rebranded it for retail sales.
Who invented the Princess Cut diamond? Bez Ambar invented the square brilliant diamond in 1979, originally called the Quadrillion Cut™. De Beers recognized the invention with its Diamond Award. The name “Princess Cut” was introduced by Lex Polished Diamonds when they licensed the cut from Bez.
Does the Quadrillion Cut look different from a standard Princess Cut? A Quadrillion cut to Bez Ambar’s original proportions will typically return more light than a commodity princess cut. The facet angles in mass-produced princess cuts are often optimized for rough yield rather than light performance. Same geometry; different execution.
What makes a Princess Cut diamond well-cut? Table percentage between 62–72%, depth between 64–75%, length-to-width ratio close to 1.00 for a square, and minimal bow-tie effect under direct lighting. GIA does not issue a cut grade for princess cuts the way it does for rounds, so these proportions must be evaluated manually or reviewed with the selling jeweler.
Can I get a Quadrillion Cut diamond from Bez Ambar? Yes. Bez continues to cut Quadrillion diamonds in his Los Angeles studio. Contact the studio directly for availability and specifications.
Continue Reading
- Rose Cut Diamond Rings
- Round Brilliant Cut: Why Cut Quality Determines Everything
- Trillion Cut Diamonds: What They Are and How They Are Used
Explore the Bez Ambar diamond education guide.
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