Making the cut: A to Z diamond cuts

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» Innovative Diamond Cuts & Shapes
» Diamond Cuts: A Brief History
» A moment with the father of modern brilliance: meet Sir Gabriel Tolkowsky

Of the famous four ‘C’s of diamond assessment, none is more important than cut. As the only element of a diamond’s appearance that can be controlled by human hands, the cut has the power to make – or break – a stone’s value.

“Cut is the heart of the diamond,” says Maulin Shah, director of World Shiner.

“It is the most important characteristic. If the cut isn't nice – the stone could be D colour and internally flawless, but it won't sparkle.”

While the vast majority of the world’s diamonds are cut as round brilliants, master cutters and designers worldwide have explored new ways to differentiate stones, enhance a diamond’s natural beauty to its greatest potential, and support the creativity of jewellers.

The history of branded or ‘proprietary’ cuts – those that were trademarked or even patented – can be traced back to one of the most venerable diamond cutting houses, with Joseph Asscher, co-founder of Royal Asscher, who created the Asscher cut in 1902.

While reports vary over whether Asscher patented the cut – the Gemological Institute of America’s journal, Gems & Gemology, asserts that he did – it has since become a generic cut; an updated version, the Royal Asscher cut, was patented in 2002.

Similarly, the 66-facet Radiant cut – invented by New York cutter Henry Grossbard in 1977 – was once a patented design and has since become standard industry terminology, as has the Princess cut, which was developed by Bez Ambar and Israel Itzkowitz in 1979, strongly influenced by Basil Watermeyer’s patented Barion cut and Arpad Nagy’s Profile cut.

Garry Holloway – director of Holloway Diamonds and inventor of the IdealScope, Holloway Cut Advisor (HCA) and Angular Spectrum Evaluation Tool (ASET) – calls the Asscher, Radiant, and Princess cuts “the only three successful branded cuts”, though he laments, “The GIA have never used these names and this provides confusion for retail salespeople and consumers.”

Branded breakthrough

In the late 1990s and early 2000s, an influx of proprietary cuts and shapes entered the market, largely driven by “radical changes in the diamond pipeline, widespread reliance on standardised price lists, advances in diamond cutting technology, and falling profit margins throughout the industry”, according to Gems & Gemology.

Many did not withstand the test of time.

“The branded cuts were largely developed as ways to improve yields or charge more for a few extra facets,” Holloway says. “The yield-increasing diamonds were the worst, essentially turning an 80-point Ideal cut round diamond hiding inside a rough into a 1-carat disaster.

“Human vision – when confronted with miniscule flashes from a 100-facet half-carat diamond – sees ‘mush’,” he explains.

“Side by side [with classic cut diamonds], they just didn’t stack up.”

And when it comes to selling a diamond, sparkle is, of course, key. “Maximum scintillation and fire is what customers want to see,” says Cindy Eidukevicius-Jones, diamond trainer and marketing and merchandise manager at the Nationwide Jewellers buying group.

“A diamond needs to show how lively and bright it can become.”

However, a select few proprietary cuts managed to provide enough of an advantage to jewellers and appeal to consumers to maintain an ongoing presence in the market.

Russian manufacturer Kristall Smolensk’s 89-facet, octagonal-shaped Phoenix cut, developed in the ’90s, is still available today, as is the Dream cut – a modified square cut patented in 2002 – from US manufacturer Hearts On Fire, which is now part of Chow Tai Fook Jewellery Group.

Lili Diamonds’ Crisscut and Lily cut, released to the market in 1996, are also still available and the company has since developed four more internationally patented designs: Crisscut Cushion, Orchidea, Wonder and the Meteor, a decagonal-shaped diamond with 71 facets, in 2010.

Above: Loose Alphabet Cut diamonds by Kunming Diamonds; Alphabet Cut diamonds set in necklace by K Kane Jewellery	Above: Rose cut diamonds, courtesy; Kunming Diamonds

Speaking to Jeweller in 2018, Dotan Siman-Tov, managing director Lili Diamonds, said, “There are several other successful patent diamonds other than Lili Diamonds around the world, but many suppliers found that it’s one thing to invent it [a new cut] and another thing to market it and that’s not easy. There is a story to build for each stone.”

Siman-Tov believed the problem was a lack of differentiation: “The new cuts were not dramatically different to the average consumer, whereas our cuts are different because, for example, we have the Lily Cut and Orchidea that are flower shapes and the Crisscut and the Crisscut Cushion are different facets than, let’s say, the regular emerald or regular cushion.”

Patented cuts comprised approximately 60 per cent of Lili Diamonds’ sales in 2018, commanding price premiums and manufactured on larger stones of five to 10 carats.

Indeed, Holloway notes that cuts incorporating extra facets work best on stones “two to 10 times larger than what is usually produced".

The year 2018 also marked the patent of eight diamonds marketed as the ‘world’s brightest’: the Sirius Star 80 Round, Sirius Star 100 Round, Sirius Star Cushion, Sirius Star Cushion 100, Sirius Star Square, Sirius Star Octagon, Sirius Star 88 Round and Sirius Star Oval.

Developed by master cutter Mike Botha and licensed by Dharmanandan Diamonds, the cuts were marketed to offer “additional light performance compared to a round brilliant cut and address the retailer’s issue of shrinking profit margins.”

In particular, the Sirius Star 80 was said to feature greater scintillation and increased light return, improved brilliance and higher visual appeal than various other round cuts.

Its 80 inclined facets include an eight-pointed star pattern in the pavilion with 100 per cent light return while the Sirius Star 100 features a 10-pointed version.

Botha said at the time, “This is a tremendous milestone for the Sirius Star brand as Dharmanandan has the depth of expertise and global reach to carry the brand in adequate inventory in all the sizes and clarity necessary for successful distribution.”

That same year, the GIA established a Proprietary Cut Program which includes branded cut names and descriptions on its diamond reports.

From left to right: Bez Ambar Blaze Solo cut; Asprey cut; Buddha Cut diamond set in pendant; Loose Buddha Cut diamond;
Above: Lili Diamonds	Above: Nicole Mera ring featuring Rose cut and Round Brilliant white diamonds and cushion-cut yellow diamond	Above: Calleija Glacier cut diamond ring, courtesy Calleija.

Back to basics

Of course, the vast majority of jewellers are well aware of the power of cut – Shah notes that the Australian market is particularly well-educated among World Shiner’s international customer base.

Yet there are still persistent misconceptions when it comes to avoiding poorly-cut stones, particularly when searching for niche products such as fancy shapes, or purchasing fancy-colour diamonds.

First and foremost, it is essential to understand that a diamond’s cut is not a single attribute, but rather refers to several different elements – not including the shape.

“Cut and shape can be confused,” Eidukevicius-Jones explains. Shape is whether the diamond is round, pear shape, cushion, etcetera; cut is how the stone has been manufactured/polished, and whether it is graded Excellent, Very Good, and so on.”

Many patented designs include both cut and shape, such as Lili Diamonds' Lily Cut.

John Chapman, director Gemetrix and Delta Diamond Laboratory, adds, “‘Cut’ has mixed connotations – even to diamond dealers. It encompasses several different attributes that include proportions, angles, symmetry, and facet junctions.”

Grading laboratories“distil these properties into grades that can be compared to a standardised reference”.

While the GIA, International Gemological Institute (IGI) and HRD Antwerp use a five-point scale to grade cut, ranging from Poor to Excellent, the American Gem Society (AGS) includes a sixth grade above Excellent, Ideal.

Says Chapman, “For round brilliants, the parameters are well understood – table width 53 per cent, pavilion depth 43 per cent, and crown height 16 per cent.

A diamond close to those specifications would be graded ‘Excellent’ for proportions and outside these ranges, proportion grades of Very Good, Good, Fair, and Poor have been defined.”

He adds, “The advent of scanners that can accurately profile a diamond and measure its proportions, facet angles and symmetry has allowed objective measures of the cut.

“Departures from this ideal cut are detrimental to the appearance of a stone through loss of brilliance, fire, and apparent size.”

And though not an official term, a diamond may also be referred to as ‘Triple Excellent’ – also noted as XXX or triple-ex – if its proportion, symmetry, and polish have all been graded as Excellent.

While the cut grades are well-established within the industry, Holloway says the biggest misconception about diamond cuts is “that Triple Excellent round cut diamonds are excellent diamonds”.

“ Excellent-grade round brilliant cut diamonds have changed over the past few years in that there has been a reduction in the diameter of particular sizes... The end result is a 'lumpier' or 'fatter' stone.”

Abraham Tok, Tok Bros

“Seventy-two per cent of round diamonds submitted to the GIA receive the top cut grade of Excellent – the standard is so lenient you can drive a truck sideways through it!” he says.

Meanwhile, the Hearts and Arrows descriptor – introduced by the Japanese diamond industry in the 1980s and brought to the US market in the early 1990s – can add another layer of confusion.

“The concept of Hearts and Arrows was introduced as a way of determining if a round brilliant has been cut with the right proportions,” Chapman says.

Commanding a premium price, these diamonds are precision-cut for physical and optical symmetry, resulting in the namesake pattern appearing when viewed through a special light scope.

“Every Hearts and Arrows diamond will be graded Triple Excellent for cut, symmetry
and polish, but not every Triple Excellent will necessarily be graded as a Hearts and Arrows diamond,” explains Eidukevicius-Jones.

IGI and HRD Antwerp offer Hearts and Arrows certification, though the GIA does not.

Notably, a Hearts and Arrows diamond may not always display optimal brilliance.

A question of quality

Since the GIA began grading cut quality in 2006, manufacturers have adapted their products in line with Excellent-grade proportions – leading to both positive and negative outcomes.

As the GIA itself notes on its website, “A diamond’s proportions can help predict how well a diamond will deliver brightness, fire and scintillation.

"However, an important outcome of GIA’s cut research was the finding that there is no single set of proportions that defines a well-cut round brilliant diamond.”

On the positive side, Shah has observed an overall increase in diamond cut quality, in part due to increased education, awareness, and demand from the jewellery market for stones that fit the standardised cut grades – alongside improvements in diamond-cutting technology.

“Worldwide, Excellent cut stones are becoming more popular, so manufacturers are producing more goods to fit that standard.

"Due to the latest machinery innovations, manufacturers now also have better results from the rough, so there are, overall, better stones coming to market,” he explains.

“Usually, if a jeweller asks for an Excellent cut round diamond certified by major laboratories such as the GIA, IGI, HRD Antwerp, or the Australian labs, they will get a nice cut stone,” Shah adds.

“Different polishers have their own ‘recipes’ for extracting the most colour and some make a livelihood out of recutting diamonds to achieve a more valuable colour grade.”

John Chapman, Delta Diamond Laboratory and Gemetrix

However, while this standardisation and wide adoption of the GIA standards allows for easier comparison between stones, the system is not perfect.

Abraham Tok, director Tok Bros, says, “The current GIA cut grade standard is acceptable as it has provided a standardised format for objectively comparing one diamond’s cut grade to another, however, it can be improved by tightening the parameters that constitute an Excellent cut grade,” he says.

Holloway points out that the standards are also not necessarily enforced by grading laboratories.

“More than 10 per cent of GIA-graded Excellent cut diamonds are deeper than 63 per cent, and the GIA teaches that 62.9 per cent is the maximum allowable depth percentage,” he says.

“When queried on this, the GIA explains that [its proprietary cut-assessment software program] Facetware adds the crown height, girdle thickness and pavilion depth percentages to arrive at depth percentage. So, clever cutters have developed workarounds – and GIA allows it!”

Indeed, Tok has observed that “Excellent-grade round brilliant cut diamonds have changed over the past few years in that there has been a reduction in the diameter of particular sizes”.

“A 1-carat round with an Excellent cut grade usually would have a diameter of 6.4mm–6.5mm, while a 1.50-carat would have a diameter of 7.4mm–7.5mm; now, you can find plenty of examples of 1-carat and 1.50-carat round diamonds, certified XXX by GIA, with diameters under 6.3mm and 7.3mm, respectively.

“The end result is a ‘lumpier’ or ‘fatter’ stone that has higher crown angles, increased depth percentages and thicker girdles. The extra weight to push the diamond into the [more valuable] 1-carat and 1.50-carat size ranges is hidden in these proportions in order to extract more value/ yield from the rough diamond.”

He adds, “This generally has a negative impact on the appearance of the diamond for jewellers as it is visually smaller when compared side-by-side with a diamond that was cut to the original Excellent parameters; 0.1mm–0.2mm may not sound like much as an overall measurement, however, when comparing diamonds this is a significant difference that is easily noticeable to the trained eye.”

Holloway points out a further problem of transparency being included in the clarity grade rather than the cut grade, meaning “a diamond can have an Excellent cut grade – or even top performance with my Holloway Cut Advisor – but it can still be as dull as dishwater.”

“In theory, a black diamond could receive a XXX cut grade,” he adds, explaining that the GIA's and other laboratory's jargon can result in confusion for both jewellery retailers and consumers alike.

“The worst is 'Clarity grade is based on clouds not show' which means the clouds are not plotted on the clarity image on a full certificate,” Holloway adds.

“With fancy shapes, it comes down to the dealer. A diamond dealer with a solid reputation, extensive experience, and a loyal existing customer base will be able to give good advice on fancy shapes.”

Maulin Shah, World Shiner

Alongside brilliance and fire, cut also impacts the other ‘Cs’ – it can both saturate and soften a stone’s colour, remove inclusions to improve clarity, and make a stone appear larger than its carat weight would otherwise imply.

Exceptions and misconceptions

With the rise of custom jewellery design – particularly for engagement rings – fancy shapes such as marquise, kite, and heart are becoming increasingly popular.

Yet none receive a standardised cut grade on a certificate, whether graded by the GIA or another laboratory, in the same way as a round brilliant. Even classic shapes like cushion, pear, and oval do not receive a full cut grade.

Says Holloway, “Simply put, most jewellers have no idea that the GIA does not grade cut proportions for any fancy- shaped diamonds.”

This also presents a challenge for diamond suppliers, with Shah noting, “It is definitely harder for fancy shapes because none of the labs write the cut grade on the certificate – they only grade rounds for the cut.

“For those other shapes, the report will mention things like polish and symmetry, but there won’t be a cut grade.”

Indeed, the greatest selling point of fancy-shaped diamonds – their unique appearance – makes them difficult, if not impossible, to standardise.

“Non-round shapes are not guided by nearly as much specification as round brilliants,” says Chapman.

“There are no ‘standard’ proportions – even for cushion cuts or ovals – against which they can be graded. Though symmetry and faceting can be graded, each lab offering such a grade will have its own criteria for what constitutes good or poor symmetry.”

Adds Tok, “The appeal of fancy shapes is subjective. Different customers prefer different proportions in their fancy shapes; for example, some customers prefer pear shapes to be longer and some prefer oval shapes to be rounder.”

When it comes to sourcing fancy shapes, Shah advises jewellers to place their trust in a respected diamond supplier.

“With fancy shapes, it comes down to the dealer. A diamond dealer with a solid reputation, extensive experience, and a loyal existing customer base will be able to give good advice on fancy shapes.

“They will have the knowledge of stone ratios and be able to make suggestions and offer a selection, and a replacement stone if the customer is not happy.”

Holloway suggests jewellers learn to use the ASET, which he developed for the AGS, to assess fancy shaped diamonds for light ‘leakage’ themselves.

Further complicating the question of cut are fancy colour diamonds.

“Cuts for fancy colours are in a different class than colourless diamonds,” says Chapman.
“The objective of the light within the stone is quite different between the two types. For colourless diamonds, the ‘pathlength’ of light within a stone is minimised, whereas for coloured diamonds, the art – or rather science – is to maximise the pathlength to deepen the colour.”

Simply put, the deeper the pavilion, the farther light can travel within the diamond, which can create a richer and more intense colour.

The key determinants of value for fancy colour diamonds are the saturation and vibrancy of that colour, and the size of the stone; therefore, cutting and polishing these diamonds is a delicate balancing act.

Typically, mixed cuts such as the Radiant are preferred as they intensify colour; this is particularly evident in diamonds toward the end of the classic D to Z colour grading scale, which, when cut appropriately, can be transformed into more valuable fancy yellows.

Says Chapman, “Different polishers have their own ‘recipes’ for extracting the most colour and some make a livelihood out of recutting diamonds to achieve a more valuable colour grade.”

Avoiding the traps

As in most areas of the jewellery trade, education is key for jewellers in sourcing quality material; it is also a useful sales tool when discussing diamonds with customers. “Jewellers should educate themselves on the ideal parameters and use that knowledge to help their customers find great diamonds,” says Tok.

Chapman echoes this observation; “Most consumers are, quite reasonably, not versed in what is a good cut and what to look for to assess brilliance and fire, so some retailers have come to their rescue with tools to help them,” he says.

“An IdealScope allows a view of the behaviour of light in a diamond from its refractions and reflections, and there are other fancier tools that show light leakage and brilliance with moving light stages, computer processing and graphic outputs of a stone’s light performance.

“Several gem labs show these diagrams on their reports with areas of red, green and blue denoting how the light is behaving.”

Eidukevicius-Jones advocates a hands-on approach: “Look at the diamond and move it around even before you pick up a loupe. First impressions last!” she says.

Whether a proprietary cut, fancy shape, fancy colour, or classic round brilliant, there is no overstating the importance of understanding a diamond’s cut and the impact it has on the overall beauty and appeal of a stone.

In order to deliver the best possible service, jewellers must both educate themselves and cultivate relationships with knowledgeable, reliable diamond suppliers in order to procure stones with outstanding sparkle – the stones with which consumers can’t help but fall in love.

INNOVATIVE DIAMOND CUTS & SHAPES WHEN TRADITIONAL JUST WON'T DO
Sirius Star Cushion 116 Facets by Mike Botha	Astralis Round Brilliant 89 Facets by Sir Gabriel Tolkowsky	Cherry Blossom/Sakura 87 Facets by Tokyo Kiho Co	Crisscut 77 Facets by Christopher Slowinski & Lili Diamonds	Brilliant 10 71 Facets by Yair Shimansky
Sirius Star 100 100 Facets by Mike Botha	Sirius Star 88 88 Facets by Mike Botha	Crisscut Cushion 85 Facets by Christopher Slowinski & Lili Diamonds	Lily Cut 77 Facets by Lili Diamonds	Ashoka 62 Facets by William Goldberg
Blue Flame 89 Facets by Bernard Van Pul & Koen Van Ishoven	Sirius Star Octagon 88 Facets by Mike Botha	Padma Round 86 Facets by Dharmanandan Diamonds	Cupio Cut 73 Facets by KP Sanghvi & Sons	Orchidea 61 Facets by Lili Diamonds
Padma Cushion 88 Facets by Dharmanandan Diamonds	Sirius Star Square 88 Facets by Mike Botha	Sirius Star 80 80 Facets by Mike Botha	Meteor 71 Facets by Lili Diamonds	Quadrillion 49 Facets by Bez Ambar & Ygal Perlman

DIAMOND CUTS
A BRIEF HISTORY

A Moment with the Father of modern brilliance
INTERVIEW WITH SIR GABRIEL TOLKOWSKY

Above: A selection of diamond cuts developed by Sir Gabriel Tolkowsky from the Flower Cuts and Sea Shell Cuts collections. Born in Tel Aviv in 1939 to a family of diamond cutters – including his uncle Marcel, credited as the inventor of the round brilliant cut – Sir Gabi was trained by his father Jean and at the age of 16, was tasked with polishing a 100-carat emerald-cut diamond. In 1975, he began working with De Beers for whom he developed the Flower Cuts collection. In the 1980s, Sir Gabi and his son Jean Paul – also a master cutter – were secretly commissioned to cut the Unnamed Brown, a 755.5-carat brown stone unearthed at the Premier Mine in South Africa. An underground workshop, free of vibration, was constructed to ensure no damage came to the stone as it was meticulously whittled into a 545.65-carat Golden Jubilee Diamond, which remains the largest cut and faceted diamond in the world – outweighing even the Cullinan I, which had held the title since 1908. The stone was completed in 1990 and later became part of the Thai Crown Jewels. When De Beers unearthed a 599-carat rough in South Africa in 1986, Sir Gabi was also selected to lead an expert team to transform it into what would become the world’s largest D Flawless stone, The Centenary Diamond. The rough was so fragile and so valuable, that no heat or laser could be used in the initial cutting process. Gabi Tolkowsky holding the completed Centenary diamond Years later, Sir Gabi recalled, “I will never forget how I worked on the Centenary for 154 working days – an entire working year – carving and carving away with my bare hands. I removed more than 50 carats before we started polishing.” The finished diamond – weighing 273.85 carats with a modified heart shape – was completed in February 1991 and unveiled in May that year, insured for more than $US100 million. Drawing from techniques developed during the polishing of the Centenary and the Golden Jubilee Diamonds and from the De Beers Flower Cuts, Sir Gabi created the Gabrielle cut, known as the first ‘triple brilliant’ and which was later sold throughout Europe, Asia, and the US. Founding his namesake company Gabi S Tolkowksy & Sons in Antwerp, Belgium, in 1995, he later created the Sea Shells Cuts collection. In 2003, he was presented with the title Chevalier de L'Ordre du Roi Leopold II (Knight of the Order of King Leopold II) for his services to the diamond industry. Here, Sir Gabi discusses his experiences and legacy as the world’s foremost master diamond cutter. What was it like to grow up in a family with such a strong connection to diamonds and diamond cutting? GT: I was the sixth generation, learning cutting and polishing from my father Jean Tolkowsky, who cut and polished as a young boy of 10 years old together with his cousin Marcel Tolkowsky, learning from their fathers and uncles. So it was natural to attract my own wish to become a diamond cleaver, cutter and polisher.  What are your fondest memories of you career in the diamond industry? GT: Having participated in the planning and creations of the Flower Cuts, the Sea Shells Cuts, and others, and the Centenary Diamond and Golden Jubilee. You were responsible for cutting the largest facted diamond in history, the Golden Jubilee. How did this come about and what did this process involve? GT: Without having a team of 15 expert scientists, technicians, security guards and master diamond cutters that communicated daily with me during three long years, I would have never been able to achieve the uniqueness of such a creation. Together we realized that every single diamond is effectively an individual that will attract every human’s senses; each one of them is a unique beauty. As it is said, “Beauty is altogether in the eye of the beholder.” This, without any doubt, was and still is the basic reason for humans to continue to manufacture and deal with diamonds. How has diamond cutting evolved over time, both as an art and commercially? GT: No matter what the position is of humans that are involved in transforming a rough diamond into a polished one, they are marking art that allows them also to be commercially busy if they wish. They are all part of a unique artistic movement. Above, left to right: Golden Jubilee Diamond, 545.65 carats; Centenary Diamond, 273.85 carats   Where is the centre of innovation, today, in terms of diamond cutting? GT: Without any doubt, due to the evolutionary period that we are witnessing, centres of innovation do exist and will continue to develop in various parts of the world. This is because approaching beauty is a normal human evolution; it allows people – men and women – to express themselves according to their cultural environment. As a matter of fact, beauty is not only an artistic reaction, but also a way to wish, hope and dream – beauty is a haven of peace! Without any doubt, it is my wish to continue the legacy of the importance of beauty by my children and grandchildren.

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