DIAMOND COLOUR & GRADING

Diamond colour is a visual characteristic that makes them unique and affects sparkle. Diamonds are available in many colours and tints. While fancy colour diamonds are highly valuable, the majority of people prefer white diamonds for engagement rings. Fancy coloured diamonds, those that have more vivid shades like pink, green, yellow and others are graded on a different scale. White diamonds are graded on a different scale. GIA is the worldwide standardised and most commonly accepted scales to grade diamond colour. Prior to this standardisation, various terms like cape, light yellow, very light yellow, numeric scales, jager, river and wesselton were used in different colour scales. However, GIA has standardised the diamond colour grade on a D-Z scale. Always be sure to purchase a certified GIA diamond scale to ensure that you are getting the true value of your purchase. All diamonds on the GIA D through Z scale are considered white although on the lower end they can have a tinge of yellow colour. Colour is a natural element in diamonds. As diamonds grow under the earth over millions of years, trace elements commonly exist in diamonds causing a yellowish or brownish tint. It is more common for diamonds to have some of this tinting than to be absolutely colourless. This shading of colour varies in hue, tone and saturation.

Diamond colour is difficult to identify but subtly distracts the eye from seeing sparkle. The human eye will rarely know the colour is the problem, but colourless diamonds will sparkle more, while yellowish or brownish tinted diamonds will sparkle slightly less. Colour is one of the 4 major C’s of diamonds. Diamond colour, in terms of grading, is determined by the “lack” of colour in a diamond; less colour a diamond has means higher the colour grade. Colour is based on overall body colour of a diamond. Because the changes in colour hue, tone and saturation are so subtle, GIA developed a grading scale, commonly known as the D to Z scale. Diamonds are assigned grades based on where they fall in the ranges between letters from D to Z.

Diamond colour is grading by evaluating the body colour of the diamond on a pure white background, face down. From the image below, you can see the diamond has no tint of yellow. This is a D-colour stone. Gemologists will often use master stones or a GIA verified set of cubic zirconia with the correct grade colour shading. If the diamond has more yellow than one but less than the other, it will receive a grade in that range. For example more yellow than F, but less than G would be a G colour diamond. Grading colour is subjective and requires multiple sets of eyes to validate and verify the accuracy of the grade. After the body is examined, the stone is flipped over and also viewed face up once to further confirm the grade. After all, diamonds are rarely viewed face down - their face up appearance is what counts most!

COLOUR SCALE

In the colour grading scale, D is the highest colour and Z is the lowest. This colour chart shows how the colour of a diamond changes visually across the scale.

D - F: Colourless - diamonds in this range have no colour or very minute traces of colour that can only be identified by trained gemologists and typically need to be compared to higher or lower graded diamonds to accurately identify the colour. Less than 1% of all gem quality diamond fall in this range.

G - J: Near Colourless - these diamonds have minor traces of colour that may be identified by trained eyes. The G/H colour diamonds are most popular because they balance value and lack of colour. Minor sparkle distractions can be noticed in I/J colours, however these diamonds still sparkle very brilliantly and have great value, when balancing the other C’s. The near colourless range represents the top 15% of all gem quality diamonds.

K - M: Faint - diamonds with K, L and M colours tend to have a faint yellow or brown tinge. The colour does affect the diamond’s sparkle by very slightly dulling it. When examined, the colour may be recognised in jewellery. These diamonds represent the top 40% of all gem quality diamonds. NB Jewellers® does not carry colours below L.