Diamond guide

The 4C’s

Diamond Shapes

There are many types of diamond cuts and shapes to choose from, and the one you select should be based on your taste and preferences. If you are buying a gift for your loved one, such as an engagement ring, it is a good idea to find the perfect diamond shape for your partner. Here are the types of diamond shapes you can choose from when buying diamond jewellery.

Round Cut

Select the diamond shape for the centre store that best suits your style and personality. The Popular shapes are listed out below.

Oval Cut

Perfectly proportioned and unique, the oval shape diamond also has a similar brilliance to that of the round diamond.

Cushion Cut

The cushion cut diamond features rounded corners and large facets to increase brilliance. This diamond shape is loved for its timeless appeal and has been a favourite for over a century.

Emerald Cut

With its pavilion cut in rectangular facets to create an elegant finish, the emerald diamond shape is truly unique.

Heart Cut

The ultimate symbol of love and adoration, the heart diamond shape is perfect for the romantics amongst us.

Marquise Cut

Originally the marquise diamond shape was commissioned by Louis XIV of France. Its elongated shape is perfect for those looking to maximise carat weight.

Diamond Carat Size Chart

Carat	Millimeter
0.25ct	4.0mm
0.50ct	5.2mm
0.75ct	5.8mm
1.00ct	6.5mm
1.25ct	7.0mm
1.50ct	7.2mm
2.00ct	8.0mm
3.00ct	9.2mm

Carat	Millimeter
0.25ct	5.12x3.41mm
0.50ct	6.3x4.4mm
0.75ct	7.35x5.07mm
1.00ct	7.7x5.6mm
1.25ct	8.4x6mm
1.50ct	8.7x6.4mm
2.00ct	9.7x6.8mm
3.00ct	10.89x8.07mm

Carat	Millimeter
0.25ct	3.65x3.58mm
0.50ct	4.7x4.4mm
0.75ct	5.78x4.76mm
1.00ct	6x5.2mm
1.25ct	6.6x6mm
1.50ct	6.8x6.4mm
2.00ct	7.3x7.2mm
3.00ct	8.53x8.11mm

Carat	Millimeter
0.25ct	5x3mm
0.50ct	5.2x3.8mm
0.75ct	5.89x4.25mm
1.00ct	6.5x4.8mm
1.25ct	7.3x5.3mm
1.50ct	7.6x5.5mm
2.00ct	8.4x6.2mm
3.00ct	9.16x7.21mm

Carat	Millimeter
0.25ct	3.96x4.11mm
0.50ct	5.5x4.6mm
0.75ct	6.41x5.79mm
1.00ct	6.8x5.8mm
1.25ct	7.8x6.6mm
1.50ct	8x6.9mm
2.00ct	8.8x7.5mm
3.00ct	9.29x9.48mm

Carat	Millimeter
0.25ct	6.54x3.27mm
0.50ct	8.4x4.2mm
0.75ct	9.53x4.83mm
1.00ct	10.4x5.2mm
1.25ct	11.65x5.6mm
1.50ct	12x6mm
2.00ct	13.4x6.5mm
3.00ct	14.02x7.48mm

Diamond Colour

When choosing diamonds, colour is a very important factor to consider. Rarity and purity are measured by a diamond’s lack of colour. Higher quality diamonds will have a pure, bright white appearance whereas those lower in quality will have noticeable colour, and to the untrained eye, this can be tricky to spot.

GIA Colour Grading Scale

Diamond clarity scale chart

The Gemological Institute Of America (GIA) uses the GIA Diamond Clarity Scale to assess a diamond’s clarity. The GIA clarity scale ranges from I (included) to FL (flawless) and includes subgrades that provide more information about the visibility of inclusions in the diamond. Each grade reflects the visibility and size of inclusions under 10x magnification, and these factors determine the overall rarity and value of the diamond.

FL - Flawless

Flawless (FL) diamonds have no blemishes or inclusions visible under 10x magnification. Diamonds graded as Flawless are very rare as inclusions are naturally occurring.

IF - Internally Flawless

Internally Flawless (IF) diamonds have no visible inclusions under 10x magnification.

VVS1/VVS2 - Very Very Slight Inclusion

Very Very Slight Inclusion (VVS1/VVS2) diamonds have only slight inclusions that are difficult for a skilled grader to see under 10x magnification.

VS1/VS2 - Very Slight Inclusion

Very Slight Inclusion (VS1/VS2) diamonds have minor inclusions that can be seen with effort under 10x magnification.

SI1/SI2 - Slight Inclusion

Slight Inclusion (SI1/SI2) diamonds have noticeable inclusions under 10x magnification.

I1 - Inclusion

Inclusion (I1) diamonds have inclusions that are obvious under 10x magnification. The inclusions affect the diamond's brilliance and transparency.

Types of diamond cuts

Each diamond is assessed and graded on its cut quality - otherwise known as the diamond cut grade. A diamond cut grade is assessed on several factors such as brilliance, symmetry, polish and fire and ranges from excellent to poor. The higher the cut quality, the more sparkle the diamond is likely to have, so you should consider the cut when buying a diamond.

Excellent Cut Diamond

An excellent cut diamond is the best diamond cut and also the most beautiful. It means that it is perfectly proportional and has the best brilliance, symmetry, polish and fire. An excellent or ideal cut diamond reflects almost all the light that enters it, so it sparkles beautifully.

Very Good Cut Diamond

A very good cut diamond is almost the same compared to an excellent cut diamond. It still enables most of the light that enters it to reflect but attracts a lower price.

Good Cut Diamond

A good cut diamond reflects a substantial amount of light that enters it. The diamond does not have the same amount of fire or brilliance that an excellent cut or very good cut diamond has, but it is a more affordable choice for those on a budget.

Fair Cut Diamond

A fair cut diamond typically reflects a small portion of light. For those looking to maximise the carat weight over other things, a fair cut diamond may be the only choice for a higher carat weight on a budget.

Poor Cut Diamond

A poor cut diamond is a diamond that has been cut too deep or too shallow. When this occurs, the diamond will lose significant amounts of light. The only benefit of this type of diamond is the price. A diamond that is a poor cut will be significantly lower in price than any other diamond cut grade while also lacking sparkle.