Joseph Asscher was the second-generation head of the Royal Asscher Diamond Company, founded in Amsterdam in 1854 by his father Joseph Isaac Asscher. In 1902, he developed and patented the cut that still bears his family name: a square step cut with deeply cropped corners, a high crown, a small table, and a deep pavilion — engineered to produce the mesmerizing "hall of mirrors" optical X that distinguishes it from all other step cuts.
The Asscher company was already among the most prestigious diamond houses in the world when Joseph developed his cut. Two years later, in 1907, the British government commissioned I.J. Asscher & Company to cleave and cut the Cullinan diamond — at 3,106 carats, the largest gem-quality rough diamond ever found. The responsibility was so immense that Joseph Asscher reportedly fainted when the cleaving blade struck successfully. The Cullinan's nine major stones and 96 smaller fragments remain part of the British Crown Jewels.
The Asscher cut fell out of fashion for much of the mid-20th century, eclipsed by brilliant cuts that produced more fire and scintillation in the showroom display cases that became standard retail environments. Its revival came in the early 2000s — not coincidentally, around the same time as a broader resurgence of Art Deco aesthetics in jewelry design. The Asscher's geometric precision and vintage character appealed to a generation of buyers who wanted something identifiably different from the round brilliant that dominated their parents' generation.
The Royal Asscher Diamond Company, still family-owned and still operating in Amsterdam, introduced the "Royal Asscher" — a modified version with 74 facets rather than the original 58 — in 2001, celebrating the cut's centenary. The modified version produces more light interaction in its steps and is protected under trademark. When you see "Royal Asscher" on a listing, it refers specifically to this patented modern variant from the original Amsterdam house.
| Factor | Why it matters for the Asscher | Recommended target |
|---|---|---|
| Clarity | Open step facets expose inclusions directly; the optical X draws the eye through the stone | VVS2 minimum for eye-clean; VS1 possible if inclusion is near the edge |
| Length-to-width ratio | The Asscher should appear square face-up; ratio deviation changes the optical X geometry | 1.00–1.05 for square appearance |
| Depth percentage | The high pavilion is intentional — depth creates the X; avoid stones cut shallow to maximize apparent size | 60–75% |
| Table percentage | Smaller table preserves the high-crown optical depth; too large a table flattens the effect | 55–65% |
| Symmetry | The geometric pattern of the Asscher is brutally exposed by misaligned facets | Excellent symmetry essential |
The Asscher cut is among the most demanding diamonds to buy well. Its open step facets require VVS-range clarity; its geometric precision demands excellent symmetry; and its optical character — the nested octagonal steps and the deep X — only emerges fully in a well-proportioned stone. It rewards buyers who understand what they are looking for and penalizes those who rely on grading report numbers alone without seeing the stone perform.