Precision Diamond Cutting — GIA-Guided Craftsmanship
A skilled diamond cutter creates converse, bright and even patterned detail and precision. When assessing diamond cutting, start with the diamond face-up. If one examines several diamonds which have high cut grades, there will be very little difference amongst the stones. A compromised cut could be noticed by dark areas in the centre, under the table or around the girdle of the cut diamond.
How diamond cutting transforms nature’s hardest gem
Did you know natural diamonds are so hard that only two things can cut through their surface? It’s true – only another diamond or a powerful laser beam can do the job. That’s why diamond cutters need special tools dusted with tiny diamond particles or fitted with diamond-edged blades. These days, they also use laser technology that can slice through diamonds with incredible precision.
You might think a diamond cutter’s primary goal is to keep as much of the original stone as possible, but there’s so much more to their craft than that. These skilled artisans are really like symphony conductors, carefully balancing four crucial elements: carat, colour, clarity, and cut. They bring out the very best in each stone, creating something far more precious than just a large cut diamond. Their expertise transforms these stones into dazzling works of art that capture light and imagination in equal measure.
The story behind diamond cutting
In 1919, master craftsman Marcel Tolkowsky cracked the code of the perfect diamond. His discovery? The same golden ratio that shapes nautilus shells and galaxies also unlocks a diamond’s inner fire.
It comes down to precise mathematics: magic happens when a diamond’s crown and height measure precisely 60% of its width. Add 58 perfectly placed facets, and you’ve got nature’s ultimate light show.
But perfection has narrow margins. Cut too shallow – below 55% – and you’ll get what gemologists call a “fish eye,” where light slips away instead of dancing back to your eyes. Cut too deep – over 65% – and you’re left with a “nail head,” its surface dotted with dark spots where brilliance should be.
“Cut” is only one part of what makes a diamond exceptional. The Gemological Institute of America (GIA) created the 4Cs – Cut, Clarity, Colour and Carat weight – as the universal method for assessing diamond quality.
The diamond’s secret blueprint
Every rough diamond holds a whisper of its final shape – two pyramids joined at their base, like nature’s own blueprint. While these stones might look unassuming when they first emerge from the earth, their crystalline structure (what scientists call trigonal) is like the diamond’s DNA. A master cutter reads these hidden patterns, seeing the perfect gem waiting in its core.
In skilled hands, one rough diamond can birth two or three treasures. A master cutter might coax both a dazzling 50-pointer and a delicate 15-pointer from a single stone, each one cut to maximise its potential while honouring its natural architecture.
Sometimes, less truly brings more value. A slightly smaller diamond cut to perfect proportions often outshines its larger cousins in both beauty and worth. Take a 99-pointer (weighing 0.99 carats) – when cut to ideal proportions, it can fetch 20% more than a full-carat stone with compromised cuts.
Choosing a diamond cut
Every diamond shape tells its own story of sparkle. Up close, nothing rivals the round brilliant’s intimate light show – its 58 facets create a dazzling dance that captivates the eye. But step back, and the emerald cut takes centre stage, its bold, architectural facets painting with light across vast spaces. It’s no accident these cuts dominate red carpets and command attention on camera.
Between these two masters of light live their artistic cousins. Cushion cuts whisper romance, princess cuts speak of modern elegance, and marquise cuts write their own rules of refraction. Each one plays differently with light, creating its own signature brilliance.
Yet in the end, a diamond’s true magic lies not in mathematics or mastery, but in that moment when the right stone catches the right eye – and sparks fly.
The diamond cutting process
The diamond cutting process typically follows these main stages:
Planning & analysis – The rough diamond is examined and mapped to determine the best way to maximise value, considering its shape, inclusions, colour, carat yield and the desired final cut.
Cleaving or sawing – The rough diamond is separated into pieces, either by cleaving along its natural planes or by precision sawing. Modern cutting often uses lasers.
Bruting – The rough pieces are shaped into the basic outline of the finished diamond. For a round brilliant, this creates the circular girdle.
Polishing – Each facet is polished to produce a smooth, highly reflective surface and the final optical performance.
Inspection & grading – The finished diamond is inspected for symmetry, polish, proportions, clarity characteristics and overall quality before being graded and, where applicable, certified.
Quality diamonds at The Diamond Works
In a Sparkling Tour, you can learn more about diamond cutting at The Diamond Works in Cape Town – and watch our diamond cutters in action.
Book now to join this experience and learn more about choosing a quality diamond.
Diamond Cutting FAQs
Which diamond cut sparkles the most?
The brilliant round cut is technically the sparkliest. Up close, it is unmatched in its scintillation. But, from afar, emerald cuts and other similar fancy cuts (pear-shaped, baguette-cut) are the sparkliest – so if you are on camera or seen across a room, pick those!
What are the different diamond cuts and shapes?
There are many, but the most popular include round-cut, emerald-cut, cushion-cut, princess-cut, square-cut, pear-shaped, heart-shaped, marquise-cut, oval-shaped, and the Asscher-cut.
How do you know you are buying a good quality diamond?
Make sure the dimensions match the carat weight, that the girdle is not overly thick or thin, that it comes with the proper certification (preferably choose GIA-certified diamonds), that it doesn’t have strong fluorescence, and that the grade is above SI2. With round brilliant cuts, ensure the proportions are correct: the height and table must be 55% – 65% of the diamond’s diameter. Every diamond at The Diamond Works meets these standards.
What is the difference between diamond cut and diamond shape?
When selecting a diamond, we consider several important quality factors. The stone’s dimensions should be appropriate for its carat weight, while the girdle should have a suitable thickness to provide a good balance of appearance and durability. We recommend independently certified diamonds, with GIA certification being our preferred choice.
For round brilliant diamonds, particular attention should be given to the stone’s proportions, including its table and depth measurements in relation to its diameter.
At The Diamond Works, every diamond we offer is carefully selected to meet these quality standards.
What happens to a diamond after it is cut?
Once the cutting stage is complete, the diamond is carefully polished to refine its facets and surface. It can then be assessed and graded before being selected for use in jewellery or further manufacturing.
How long does it take to cut a diamond?
The time required to cut a diamond depends on factors such as its size, shape, crystal structure and the complexity of the planned design. A cutter may spend considerable time studying and planning the stone before any material is removed.
Can the original shape of a rough diamond affect the finished diamond?
Yes. The natural form of a rough diamond can influence how a cutter approaches the stone and what shapes can be produced from it. Natural features within the rough may also affect how the stone is divided or positioned before cutting begins.
Why is planning important before cutting a diamond?
Once material has been removed from a diamond, it cannot simply be put back. Careful planning allows the cutter to determine how the rough stone can be divided and shaped while balancing its potential appearance, weight and overall value.
Does diamond cutting affect the size of the finished diamond?
Yes. Cutting and polishing remove part of the original rough material, so the finished diamond will weigh less than the rough stone from which it was produced. The amount removed depends on the characteristics of the rough and the intended finished design.