Diamond Cut Guide

All that glitters is not gold– it’s usually a diamond ring! But what makes the perfect diamond? How do you get so many different shapes from one rough stone? Thanks to the incredible knowledge bank at Stelios Jewellers, it’s time to explain the ins and outs of this beautiful stone with this comprehensive diamond guide.

So who, or what, initially determines a diamond’s final cut? At first inspection, the characteristics of the rough stone ‘speak’ to the diamond cutter. How deep is it? What angles are already there? These natural characteristics tell the cutter how they move through the cut process which must include proportion, symmetry and polish.


What’s in a carat?

A carat is a measurement of weight in a diamond. A metric carat equals 200 milligrams. This 200 milligrams is then divided into 100 points, allowing a jeweller to obtain a precise measurement of sale to the hundredth decimal point.



The grade of light that reflects out and around a diamond engagement ring is determined by:

  • Facet shapes and angles
  • Girdle (or perimeter) width
  • Culet size (facet at the tip of the diamond)
  • Polish and symmetry

All of these identifiers are taken into account to provide a single rating on the diamond rings’ visual performance.

Super Ideal Cut:

Extremely rare, symmetry is 100% accurate. Everything is as close to perfect as possible.

Ideal Cut:

This diamond is still a masterpiece, emitting the most brilliance and light.

Excellent Cut:

Cut to a high polish and symmetry, it contains outstanding fire and brilliance.

Very Good Cut:

Producing superior fire and brilliance, it’s similar to an Excellent Cut but is lower in price.

Fair Cut:

Much of the light escapes through the sides or the bottom of the diamond reducing the fire and brilliance.

Poor Cut:

The diamond appears dull and lifeless. Light entering the diamond escapes through the sides or the bottom.



Round Brilliant

Universally popular for its ability to produce maximum sparkle, you’ll find the Round Brilliant diamond showing off its magnificent brilliance mostly in solitaire diamond engagement rings.



The Emerald Cut comes in either a square or rectangular form. Due to its wider table – the largest facet of the gemstone – there is less brilliance playing off other facets. Cut well it is a sight to behold.



The Cushion or Pillow Cut diamond varies from square to rectangular. Each Cushion Cut will possess rounded corners. Larger facets serve to improve the brilliance and clarity.



Possessing an impressive 56 facets, the Oval Cut diamond delivers great brilliance and fire. If cut well, the Oval Cut diamond can rival the light show within a Round Brilliant shaped diamond engagement ring.



The Heart Cut holds great sentimental value for its love heart shape. Typically containing 59 facets, a skilled gem cutter is required to obtain its maximum brilliance.



Stand back and prepare for some fire! You get the better of two diamond worlds here where the elegance of the Emerald shape if cleverly combined with the brilliance of the Princess, culminating in between 62 and 70 facets.



Cut with two pointed ends, the Marquise Cut is the most delicate to produce and the most expensive of brilliant cuts. But what an outcome to the eye! With 56 light-capturing facets, it’s very popular for engagement rings.



A clear rival to the awesome Round Brilliant cut, the Princess Cut is often chosen as a stand-alone solitaire diamond engagement ring. Ideally a perfect square, it can also take on a rectangular shape.



The Pear Cut, or teardrop cut, contains 56 to 58 facets. Another popular diamond for stand-alone brilliance, the Pear Cut is a wonderful choice for an engagement ring for smaller fingers.



A squarer step-cut with an almost octagonal outline, the Asscher Cut was modified from an Emerald Cut and when compared contains more fire and light.


Diamond Cut

Quality. Depth. Portions of cut. Variations on all of these qualities will change the resulting appeal of your diamond.



This design allows light to escape out of the top of the diamond robbing any observer of a greater light display.



This is where well-proportioned, precision angled cuts achieve a brilliant appearance.



Cut the diamond too deep and even up against a diamond of a similar carat it will look smaller.

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