Quadrillion — The Square Mixed Cut That Preceded the Modern Princess
Quadrillion — The Square Mixed Cut That Preceded the Modern Princess
An early square brilliant design from the 1960s and 1970s, now largely historical
The quadrillion is an early square mixed-cut design featuring a step-cut crown and a brilliant-cut pavilion, developed in the 1960s and 1970s as part of the wider trade effort to find a square cut that produced acceptable brilliance and light return for diamonds and coloured stones. The cut preceded the now-dominant princess cut in commercial use and shares with it a similar square outline, but employs fewer facets and a less aggressive pavilion geometry. The quadrillion has been largely supplanted in current practice by the princess cut and by the various Barion derivatives, but the design remains historically significant as one of the early successful square brilliants and is still occasionally encountered in vintage jewellery.
Design and geometry
The quadrillion combines step-cut crown facets — typically three or four rows of long rectangular facets surrounding the table — with a modified brilliant pavilion divided into four pavilion mains and additional smaller facets that distribute light return more effectively than a simple step-cut pavilion would allow. The design produces a square stone with sharp corners, generally without the chamfered or truncated corners that characterise the radiant cut, and with light performance intermediate between the strong brilliance of a brilliant cut and the more restrained step-cut light return of an emerald cut.
The quadrillion's facet count is lower than that of the modern princess cut and substantially lower than that of the Barion variants, both of which evolved through systematic optimisation of pavilion geometry to maximise light return. By contrast, the quadrillion was developed largely through trade experimentation and lapidary intuition rather than through the computer-assisted ray-tracing analysis that produced later square brilliant designs.
Historical context
The quadrillion emerged in the 1960s and 1970s as part of the broader response to client interest in square diamonds and the recognition that traditional square step-cut designs (such as the basic emerald cut applied to a square outline) lacked the brilliance preferred by many consumers. The cut was offered by several manufacturers under the quadrillion name and under various proprietary names that have not survived in current usage. The princess cut, introduced in the 1980s and refined through the 1990s, offered substantially better light performance and rapidly displaced the quadrillion in commercial production.
Quadrillion-cut diamonds and coloured stones are now encountered chiefly in vintage jewellery from the period 1965 to 1985, and occasionally in custom recuts from the same era. The cut's facet pattern is recognisable on close examination, distinguishing it from later square brilliant designs.
In the trade
Modern square brilliant production overwhelmingly uses the princess cut and its variants. The quadrillion name is not in current commercial use for new production, and the term appears chiefly in trade reference works and in the descriptions of vintage jewellery being offered at auction or by specialist dealers. Buyers encountering quadrillion-cut stones in vintage pieces should not expect the brilliance and light return of modern princess cuts, but the historical and design interest of the quadrillion can be a positive feature in the right setting.
Recutting an antique quadrillion to a modern princess is technically straightforward but typically loses 15 to 25 percent of the original weight, depending on the proportions of the original stone. The decision to recut therefore depends on the relative value of historic preservation versus improved light performance, and on the size and quality of the original. Larger, finer-quality quadrillions are usually preserved in their original form; smaller or lower-quality stones may be recut where the resulting price uplift justifies the weight loss. See also princess cut, Barion cut, and mixed cut.