As printed in Canadian Jeweller, February/March 2005 issue, p. 80
By Ronald R. Dupuis, FGA, GJ

Diamond aristocrats: a history of cut

A few years ago, on a warm day in early May, a fur-wrapped woman attending one of my previews walked nonchalantly up to the case I stood behind and, in a loud voice, announced that she could never wear a piece of jewellery that had been worn by someone else. I smiled, but thought “Look what you’re missing!” November’s In Style magazine listed a number of celebrities who could take issue with her: Madonna, Cather- ine Zeta-Jones and Reese Wifherspoon all chose vintage or vintage-style diamond rings for their engagements. Clearly, scintillatingly in fact, everything old is new again, and so here is a quick refresher on the history of diamonds and their cuts.
Until faceting began in the 1500s, the brilliance of diamonds was often obscured by poor cutting. Consequently, emeralds and rubies were far more popular jewels. Diamonds were mined in large quantities in India, the source of most European diamonds until the supply began to subside in the late 17th century. Brazil was tapped as a new source in 1730, and when this supply dwindled by the middle of the 19th century, South African mines took over.

Very early diamonds – those used in India and South-east Asia – were point- or table-cut by hand and laboriously polished with diamond dust. The first facet cuts resulted in what we know as the table. The appearance of the table-cut in Europe coincides, and is likely responsible for, the first use of diamonds in jewellery during the Middle Ages. The table-cut remained popular throughout the Renaissance.

The appearance of the polishing wheel in 1350 allowed greater complexity in facet design. Experimentation resulted in the rose-cut. This is a round cut with a flat bottom and facets (anywhere from three to 24) over a domed surface. The resulting stone resembles an open rose, hence the name.
The old single-cut diamond (a modern version of the single-cut is still in use today, primarily for accent stones) appeared around the middle of the 17th century. It’s deeper than a rose-cut, and features an additional eight facets on both the crown and the pavilion. The table is octagonal in shape. This is the cut that eventually gave rise to the brilliant-cut discussed below.

Greater experimentation in cutting coincided with the discovery of diamonds in Brazil, and by the middle of the 18th century, the old mine-cut was being used, often with a cushion shape. Both it and the slightly later rounded form, known as the old European-cut, boast high crowns, deep pavilions, small tables, relatively large culets (which is rare, rendering them easy to identify) and 58 facets – 33 on the crown and 25 on the pavilion. Strictly speaking, both of these are part of the brilliant-cut family, a term that first appears in the diamond trade late in the 17th century. Both cuts are common in estate jewellery.

The growing penchant for displays of wealth during the 19th century resulted in a renaissance of jewellery design and manufacture, and diamonds remained the favorite gemstone of fashion-conscious Victorians. The old cushion shaped mine-cut proved popular in open-back settings that left the pavilion open, allowing more light to be reflected from the diamond. Trembling brooches or necklaces – pieces with stones projected on wires that gently moved or trembled – also helped to bring the diamonds to life.

Thanks to the massive increase in availability and quality of diamonds coming from South Africa in the late 19th century,

diamond jewellery became even more common. With the invention of the modern diamond saw in 1918, a plethora of cutting styles appeared. The Asscher-cut (1902), which predated the appearance of the diamond saw, was short-lived in popularity, especially once the ideal brilliant-cut was defined by mathematician Marcel Tolkowsky in 1919. His publication Diamond Design: A Study of the Reflection and Refraction of Light in Diamond prompted the creation of the early modern brilliant-cut, and encouraged many cutters to adopt his proportional approach. The resulting cut was often referred to as the American Ideal. Recently, things have changed again. The Asscher-cut is enjoying renewed popularity, and the Gemological Institute of America has recently completed research that disproves the notion that the Tolkowsky cut is the so-called “ideal.” GIA now refers to a range of proportions that combine to maximize light return, and is on the brink of introducing a cut grading system for its grading reports.

Transitional brilliant-cuts – modified modern cuts with wide back facets – dominated from 1920-30, although step-cuts, such as baguettes, squares and emerald-cuts, started to appear in 1922. The Swiss-cut (1920-35) was similar to a single-cut, but with extra facets on the crown, and the French-cut (1920-35) was akin to the Swiss but with a more square outline. Back facets began to narrow in about 1930, giving diamonds a more brilliant look, and from 1940 to 1950, the crown height began to drop. The contemporary modern brilliant, with little or no culet, a larger table size and deeper girdle facets, was established after the Second World War.
Any market has to adjust itself to a wide range of buyers, and like my fur-draped visitor, there are some to whom only the sharp fire and flashy brilliance of modern cuts will appeal. For those who appreciate the warmth, elegance and history of older diamonds, a much more rarified and increasingly expensive supply exists. As many of these older specimens are altered to incorporate modern cuts, these aristocrats of diamond cutting history have become few and far between. Today, they often fetch premium prices because of their rarity.