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DIAMOND RATIOS - WHY proportions matter

Have you ever found yourself captivated by a display of diamonds, seemingly identical in carat weight yet vastly different in their size and proportions? This isn’t your eyes playing tricks on you. When you observe Diamonds closely for your Engagement Ring in Melbourne, you will find every single stone is cut to slightly different measurements - or to what those in the industry call Diamond Ratios. By definition ‘Diamond Ratios’ refers to the relationship between the width and length of the stone. Essentially this describes either how elongated and slender the shape of the diamond or whether it presents a more widened appearance.

But how do you know the ratio of the Diamond you’re viewing? And why should you take notice? We share in this article how to figure out a Diamond Ratio and what to look for so you can feel confident in selecting the ideal diamond for your Engagement Ring!

To discover a Diamond’s Ratio, it can be calculated by dividing a diamond's length measurement by its width measurement. This measurement is taken from the table of the stone (the top surface of the diamond/view from above). This can be taken with a gauge or can easily be found on any certified Diamond certificate (GIA, IGI, GCAL). Using these dimensions in this equation will produce the Diamond’s Ratio - which will indicate how elongated or wide a diamond’s shape is.

When a diamond's ratio is 1:1, the length will be the same measurement as its width. This produces a perfectly round or square stone. Think Round Brilliant Cut Diamond, Traditional Cushion Cut Diamond or Princess Cut Diamond - they will all have a 1:1 Ratio.

When a diamond ratio is 1:4 - 2:0, the length measurement will be significantly greater than the width and will produce an elongated Diamond Shape. A ratio in this range would generally be associated with a shape such as an Oval Cut Diamond, Emerald Cut Diamond, Radiant Cut Diamond, Pear Cut Diamond or Marquise Cut Diamond.

Common diamond ratios range between 1:1 to 1:5 and when browsing you will typically come across stones with a 1:1, 1:2, 1:3,1:4 or 1:5 Diamond Ratios.

For visual reference, see below examples of Diamond Ratios and the variation between a more uniform diamond or a more elongated shape. You can easily view the differences. 

cushion diamond engagement ring melbourne

Cushion Cut Diamond Ratio - Square Cushion, Cushion, Elongated Cushion 

radiant diamond engagement ring melbourne

Radiant Cut Diamond - Square Radiant, Radiant, Elongated Radiant  

oval diamond engagement ring melbourne

Oval Cut Diamond - Square Oval, Oval, Elongated Oval 

Note how although the length and width measurement varies for every diamond, the number of facets and the pattern remains unchanged. In all of these instances Diamond Cutters have kept the proportionality of these stones in a visually pleasing way. Emphasizing that these rare and beautiful diamond shapes can encompass a range of ratios. 

Every diamond shape has what the experts would call an ‘Ideal’ ratio or an ‘Ideal’ range. This is based on a mathematical formula so that every facet of the diamond bounces and reflects the brightest sparkle and impressive fire back to the wearer based on measurement and angle.

It is essential for optimal light reflection and dispersion, contributing to the diamond’s overall beauty.  A well proportioned diamond will also look balanced and harmonious to the eye. Slight differences in their proportions can affect their overall shape and change entirely the way in which they catch the light. The seemingly simple idea of adjusting their measurements so a diamond measures wider or longer in shape requires a high level of skill and astonishing precision to preserve their sparkle. A stone too long or too wide can distort the diamond facets, the light reflection and refraction will be impacted - reducing and diminishing a diamond’s sparkle.

The Ideal Ratios for the most popular Diamond Shapes are: 
Round Brilliant Cut - 1.0 - 1.03
Oval Brilliant Cut - 1.30 - 1.50
Radiant Cut - 1.20 - 1.50
Pear Brilliant Cut 1.45 - 1.80
Cushion Cut - 1.0 - 1.08
Princess Cut - 1.0 - 1.04
Emerald Cut - 1.30 - 1.45
Marquise Cut 1.85 - 2.1

There are several fancy shaped diamonds that are in varying elongated shapes. Radiants, Cushion, Oval, Emerald, Pear and Marquise.

Some Diamond Ratios are invented from the desire to experiment and innovate, others are a necessity to preserve carat weight. Whatever the reason, each diamond holds a different appeal with their wide range of shapes and sizes.

Diamond cutters hold a great deal of responsibility deciding the angles and measurements on the faceting arrangement. A focus on guiding light requires both technical and creative brilliance. A Diamond Cutter must consider the unique characteristics of each diamond to achieve beautiful symmetry. Get it right and they produce all the visual elements of a breath-taking diamond - producing that hypnotic sparkle that we all know and love. Get it wrong and they create distortion, shadows and dark spots within the stone, a dull diamond and all round undesirable stone.

They must not only consider the table/crown (top of the diamond) but also its depth percentage (height). Depth percentage is the diamond’s height in relation to the table. It is essential for creating the optimal light reflection and dispersion of the stone. A Fancy-Cut diamond with a Ratio too elongated for its shape can appear distorted and lifeless. Diamonds that are cut too shallow or deep can leak light and diminish their sparkle. This has a great impact on its appearance and beauty and the interplay of light.

Light and proportionality is a central theme with Diamond Ratios. Craftsmen must assess the angles and symmetry of every facet to ensure a diamond’s brilliance. A huge amount of what they’re doing is guiding the light. A well-cut and well proportioned diamond will allow light to bounce internally within the stone and exit throughout the crown (top) of the stone for the brightest sparkle. The Diamond Ratio is crucial for developing a diamond's brilliance. Determining the angles and proportions of these facets and the way in which a diamond interacts with light.

Selecting your Diamond Ratio comes down to desired appearance, there is no one-size-fits-all. However we do suggest staying within the ranges of ‘Ideal Ratios’. The industry has developed a range for the measurements for every diamond shape which are thought to optimise a diamond’s brilliance, fire and scintillation. They will be the brightest and sparkliest stones with the most flattering silhouettes. 

There is one exception when it comes to ‘Ideal Ratios’ for Diamond shapes and those are Hearts & Arrows Diamonds. Their proportions seem unusual and won’t fit under the Diamond Ratio ‘ideal’ standards. Diamond cutters have pushed the boundaries of traditional diamond shapes to create new and captivating proportions. Creating visual variety, Diamond Cuts such as the Hearts & Arrows Cut have produced an astonishing configuration of facets. With diamond shapes being released with new and interesting proportions. Focusing on the marginal adjustments of widening the facets, this technique made it possible for the highest degree of symmetry. The apparently simple concept of slightly adjusting these facets requires an extremely high skill level. A lot of clientele are drawn to their distinguished pattern. They are easily identified by their arrows pattern when viewed from above and hearts pattern when viewed from below. These slight details that might go unnoticed can be the difference of a diamond that is 3-4 whiter and brighter than the standard.

We acknowledge Diamond Cutting is an amazing talent we will likely never be able to fully appreciate.
We know the diamond looks good, but will the principles behind a diamond sparkle remain a mystery to many. They not only affect the overall shape of the diamond but also influence their brightness and sparkle. When you realise how careful and precise Diamond Cutters need to be and how they are solely responsible for directing light in certain ways, you’ll grow an even further appreciation behind their beauty.

Choosing the perfect diamond involves considering many factors. A carefully chosen diamond cut to very particular depth and angles has the ability to produce the most desirable sparkle. Diverse in their beauty, Diamonds differentiate themselves through these subtle variances. By fine tuning each diamond into differing proportions or contemporary shapes (elongated cushion cuts, oval hearts and arrows) clients can expect to see an array of beautiful elongated Diamond cuts with the same fire as a Round Brilliant Cut with equally appealing symmetry.

Visit us at Janai Melbourne and our diamond specialists can educate and guide you in to finding the ideal ratio and the diamond that is right for you. With the help of our diamond specialists at JANAI - they will guide you to create your perfect Engagement Ring in Melbourne.

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