The 4Cs

A diamond's beauty, rarity, and price depend on the interplay of the 4Cs: cut, clarity, carat and colour. The rarity of a diamond's characteristics the higher the price it demands.

The Diamond Quality Pyramid was created to help explain the 4Cs in terms of rarity. For example, a colourless diamond is at the top of the Diamond Quality Pyramid in the colour category, but if it is small, of lower clarity and cut, it will be of a lower value.

No one C is more important that another in terms of beauty and it is important to note that each of the 4Cs will not diminish in value over time unless damaged by an accident.

Cut
Refers to the angles and proportions of a diamond (see left).

Cut is also referred to as 'make' as it is the only part of the loose or certified diamonds made by human hands. The cutter not only forms the shape but the proportions too. The symmetry of the two determines the sparkle of the diamond: the better the proportions the more brilliance will be reflected to the viewer’s eye.

Colour
Refers to the degree to which a diamond is colourless.

Colours range from very white to shades of many different colours with D being the highest colour. View charts give a better idea in the area of colour for loose or certified diamonds.

Carat
Refers to the weight of the diamond.

This is measured in carats and has the biggest impact on its price. The metric carat equals 0.20 gram and is the standard unit of weight for diamonds and most other gems. If other factors are equal the more a stone weighs the more valuable it will be.

Dimensions of the diamond should not be confused with carat weight. The two are unrelated because a stone may have varying depths and the cut could make it appear bigger. There are several ways to express 1 carat:

1 ct.

200 milligrams

1/5 gram

100 points

4 grainer (not often used in retail environment)

Clarity
Refers to the presence of inclusions in a diamond.

Clarity Categories:

FL – IF
Diamonds reveal no flaws on the surface or internally. These are rare and are the most beautiful gems treasured for their absolute purity.

VVS1 - VVS2
Diamonds have minute inclusions absolutely invisible to the naked eye. Only through careful inspection with a microscope can these tiny inclusions be accurately pinpointed. The brilliance of the stone does not suffer in this category.

VS1 - VS2
Diamonds have tiny inclusions that are difficult to locate. Only a trained eye looking through a 10X loupe can pinpoint the inclusions in this category. The inclusions are nearly impossible to see with the naked eye.

SI1 - SI3
Diamonds have inclusions easily identified through a loupe. Finding flaws in this category with the naked eye is difficult. The gems in this category maintain their integrity, depending on the location of the inclusions.

I1 - I3
Diamonds have inclusions that may or may not be easily seen by the naked eye. The flaws on the stones in this category will have some effect on the brilliance of your diamond.

For expertise advice and to purchase a diamond from Roger Williams:

Call:  + 44 (0) 29 2022 1144 | Email: roger@diamondswales.com
Buy online: www.jewellerystudio.co.uk
Visit in person: Jewellery Studio, 237 Cathedral Road, Cardiff CF11 9PP, UK

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