The Asscher cut stands as one of the most consequential innovations in the history of diamond fashioning: a square step-cut with deeply cropped corners, a high crown, a small table, and a deep pavilion that together produce the mesmerising optical phenomenon known as the "hall of mirrors" effect — concentric squares of light receding toward the culet like a corridor of reflections. Developed in 1902 by Joseph Isaac Asscher at the I.J. Asscher Diamond Company in Amsterdam, the cut was not merely a stylistic preference but a precise engineering solution to the optical properties of diamond, conceived by a family that had spent generations mastering the behaviour of the hardest natural substance on earth. Its subsequent adoption as the signature stone of the Art Deco movement, its near-disappearance in the mid-twentieth century, and its dramatic revival in the early 2000s make the Asscher cut one of the most compelling narratives in gemmological history.

The Asscher Family and the Amsterdam Diamond Trade

To understand the Asscher cut, one must first understand the dynasty that produced it. The I.J. Asscher Diamond Company was founded in Amsterdam in 1854 by Isaac Joseph Asscher, and by the turn of the twentieth century it had grown into one of the most respected diamond-cutting and -polishing establishments in the world. Amsterdam had been a centre of the European diamond trade since the seventeenth century, when Portuguese Jewish merchants brought rough stones from the Indian subcontinent to the Low Countries, and the city's craftsmen had developed a tradition of technical rigour that distinguished them from cutters elsewhere in Europe.

Joseph Asscher, Isaac's son, inherited both the firm and its culture of precision. He was a master cutter in the fullest sense — a man who understood not only the mechanics of cleaving and polishing but the optical geometry that determines how light travels through a faceted stone. The step-cut tradition from which the Asscher cut derives had existed for some time in the form of the emerald cut and various rectangular table cuts, but Joseph Asscher recognised that a square format with aggressively truncated corners and a specific facet arrangement could produce an entirely different quality of light return: not the dispersive fire of a brilliant cut, but a deep, architectural luminosity that seemed to emanate from within the stone itself.

The 1902 Patent and Its Technical Specifications

The Asscher cut was patented in 1902, giving the I.J. Asscher Diamond Company exclusive rights to the design for several decades. In its classic form, the cut comprises 58 facets arranged in a step-cut pattern: a square outline with corners cropped at approximately 45 degrees to produce an octagonal girdle silhouette, a high crown relative to contemporary step cuts, a relatively small table facet, and a deep pavilion. The proportional relationship between these elements is critical. The high crown elevates the stone's profile and increases the angle at which light enters, while the deep pavilion maximises internal reflection before light exits through the crown. The result is that the stone appears to contain depth far exceeding its physical dimensions.

The cropped corners serve both an aesthetic and a practical function. Aesthetically, they soften the geometry of the square and create the octagonal silhouette that became one of the cut's most recognisable features. Practically, they protect the stone's most vulnerable points — the corners of a square-cut diamond are prone to chipping under impact — while also facilitating the setting of the stone in square or octagonal mounts. This combination of beauty and structural pragmatism is characteristic of the best lapidary design.

The patent remained in force until the 1940s, during which period the Asscher company was the sole authorised producer of the cut. Other cutters produced step-cut squares, but the precise proportional formula of the true Asscher cut was proprietary. After the patent expired, the design entered the public domain and was widely reproduced, though often with less rigorous adherence to the original proportional specifications.

The Cullinan Diamond and the Asscher Reputation

Six years after patenting his eponymous cut, Joseph Asscher was entrusted with what remains the most consequential single act of diamond cleaving in recorded history: the division of the Cullinan diamond. Discovered in the Premier Mine in the Transvaal in January 1905, the Cullinan weighed 3,106 carats in the rough — the largest gem-quality diamond ever found — and was presented to King Edward VII by the government of the Transvaal in 1907. The task of cleaving it was awarded to Joseph Asscher, whose reputation for handling exceptional rough was unrivalled.

The cleaving of the Cullinan took place in February 1908 at the Asscher works in Amsterdam. Joseph Asscher studied the stone for months before making his first strike, identifying the precise plane of cleavage that would yield the maximum number of high-quality polished stones. According to well-documented accounts, when he finally struck the stone with his cleaving blade, it split perfectly along the intended plane — and Asscher himself reportedly fainted from the accumulated tension of the moment. The Cullinan was ultimately fashioned into nine major stones and ninety-six smaller brilliants, the largest of which — the Cullinan I, or Great Star of Africa, at 530.20 carats — remains the largest polished white diamond in the world and is set in the British Royal Sceptre with Cross. The Cullinan II, at 317.40 carats, is set in the Imperial State Crown.

The Cullinan commission cemented the Asscher name as synonymous with the highest level of diamond craftsmanship. It also demonstrated that the family's expertise extended far beyond the production of a single proprietary cut: they were, in the fullest sense, masters of the diamond in all its forms.

The Asscher Cut and the Art Deco Movement

The timing of the Asscher cut's introduction proved fortuitous in ways that Joseph Asscher could not entirely have anticipated. The first decade of the twentieth century saw the beginning of a profound shift in decorative arts, away from the organic, nature-inspired forms of Art Nouveau toward the geometric, rectilinear aesthetic that would crystallise as Art Deco in the 1920s. The Asscher cut's square silhouette, its architectural step facets, and its cool, interior luminosity made it a natural companion to the design vocabulary of the period.

Art Deco jewellery, as practised by the great Parisian maisons and their counterparts in London, New York, and beyond, was characterised by bold geometric forms, strong contrasts between white diamonds and coloured stones, and a preference for platinum settings that allowed the metal to recede and the stones to dominate. The Asscher cut's octagonal outline translated beautifully into the angular settings of the period, and its step facets harmonised with the rectilinear patterns — baguettes, calibré-cut onyx, carved jade — that surrounded it in the elaborate compositions of the era's finest jewellers.

Cartier, Van Cleef and Arpels, Boucheron, and Mauboussin all incorporated Asscher-cut diamonds into their most significant Art Deco commissions. In England, the cut appeared in the work of Garrard and in the jewellery produced for the aristocracy and the newly wealthy industrial class. In the United States, it became a favoured choice for engagement rings among those who sought something more architecturally sophisticated than the round brilliant that was beginning its long dominance of the American market.

Wartime Devastation and Near-Disappearance

The Second World War brought catastrophe to the Asscher family and to the Amsterdam diamond trade as a whole. The Netherlands was occupied by Nazi Germany in May 1940, and the Jewish community of Amsterdam — which had been central to the diamond trade for centuries — was subjected to systematic persecution, deportation, and murder. Of the approximately 500 members of the Asscher family and their employees, only a handful survived the war. The company's assets were seized, its workforce destroyed, and its institutional knowledge nearly lost entirely.

After the liberation of the Netherlands in 1945, the surviving members of the Asscher family rebuilt the company, but the world they returned to was fundamentally changed. The Art Deco aesthetic had given way to the more fluid forms of the mid-century modern movement, and consumer preference in diamonds had shifted decisively toward the round brilliant cut, which the diamond industry — and particularly De Beers — was actively promoting. The Asscher cut's patent had expired, and the versions being produced by other cutters often lacked the precise proportions of the original, further diluting the cut's reputation. By the 1960s and 1970s, the Asscher cut had become something of a period curiosity, associated with antique jewellery rather than contemporary design.

The Royal Asscher Cut: A Twenty-First-Century Reinvention

The revival of the Asscher cut began quietly in the 1990s, as a broader cultural interest in vintage and antique jewellery began to influence contemporary design. Collectors and dealers recognised that original Art Deco Asscher-cut stones possessed a quality of light and a depth of character that modern brilliant cuts could not replicate, and demand for antique examples began to grow. By the late 1990s, the cut had attracted sufficient attention that the Asscher family — now in its fifth generation of diamond cutting — began to consider how to reintroduce it to the contemporary market.

In 2001, Edward and Joop Asscher introduced the Royal Asscher cut, a redesigned version of the original that added 16 facets to the pavilion, bringing the total to 74. The additional facets were positioned to increase the stone's brilliance and light return while preserving the essential character of the original — the high crown, the deep pavilion, the octagonal silhouette, and the hall-of-mirrors optical effect. The Royal Asscher cut was granted a new patent and is produced exclusively by the Royal Asscher Diamond Company, which received its royal designation from Queen Beatrix of the Netherlands in 1980 in recognition of the firm's century and a quarter of service to the trade.

The Royal Asscher cut stones are laser-inscribed with a unique serial number on the girdle and are accompanied by certificates of authenticity, distinguishing them from the many generic square step cuts that are marketed under the Asscher name in the broader trade. The distinction matters: a true Royal Asscher cut, produced to the family's proprietary specifications, exhibits a measurably different optical performance from a generic square emerald cut with cropped corners.

The Asscher Cut in the Contemporary Market

The early twenty-first century has seen the Asscher cut re-established as one of the most sought-after diamond shapes in the luxury market. Several factors have contributed to this resurgence. The broader cultural appetite for vintage and Art Deco aesthetics — expressed in fashion, interior design, and popular culture — has made the cut's period associations an asset rather than a liability. The growth of the antique and estate jewellery market has introduced a new generation of buyers to original Art Deco Asscher-cut pieces, many of whom then seek contemporary versions for their own commissions.

The cut has also benefited from high-profile associations. Several well-publicised celebrity engagement rings featuring Asscher-cut diamonds in the 2000s and 2010s brought the shape to wider public attention, and its appearance in period-set film and television productions reinforced its association with a particular quality of glamour — sophisticated, geometric, and emphatically not the default choice.

In the trade, Asscher-cut diamonds are evaluated by the same criteria as other step cuts, with particular attention paid to the clarity of the stone. The step-cut facet arrangement is less forgiving of inclusions than a brilliant cut, because the large, open facets and the deep interior reflections make inclusions more visible to the naked eye. Buyers and gemmologists alike tend to favour stones of VS2 clarity or better, and eye-clean SI1 stones command a significant premium over included examples. Colour is similarly critical: the step facets tend to concentrate colour in the corners of the stone, making lower colour grades more apparent than they would be in a brilliant cut of equivalent grade.

Legacy and Significance

The Asscher cut's history encompasses more than a century of diamond craftsmanship, surviving war, cultural upheaval, and the near-total dominance of the round brilliant to emerge as one of the defining shapes of contemporary luxury jewellery. It is a cut that rewards patience and connoisseurship: its beauty is not immediately obvious in the way that a well-cut brilliant's fire and scintillation announce themselves, but reveals itself gradually, in the depth of its reflections and the quiet authority of its geometry.

The story of the cut is also, inescapably, the story of the Asscher family — their technical mastery, their cultural centrality to the Amsterdam diamond trade, their near-annihilation in the Holocaust, and their remarkable persistence across six generations. That the same family which cleaved the Cullinan diamond in 1908 continues to produce diamonds under a royal warrant in the twenty-first century is a fact that lends the cut a historical resonance that no marketing campaign could manufacture. The Asscher cut endures because it is genuinely excellent, and because the people who created it understood that excellence, properly pursued, outlasts fashion.

Further Reading

• GIA — Asscher Cut Diamond
• Gems & Gemology — The Asscher Cut Diamond (Spring 2004)
• GIA — The Cullinan Diamond