Diamonds in Depth: Colour

Everything you need to know about Diamond Colour

People outside of the diamond trade often misunderstand the relationship between diamonds and colour. Many people think of diamonds as colourless. In reality, truly colourless diamonds are quite rare. Most diamonds used in jewellery are nearly colourless with a slight yellow or brown tint — most often very light yellow.

White or Colourless ?

Diamonds come in many colours other than yellow and brown - these are known as ‘fancy colours’. Some of the rarer fancy colours are: red, purple, blue and green. With fancy coloured diamonds, more colour usually means a higher value; so the brightest, purest colours are the most desirable. For simplicity sake, this article will only cover the normal colour range of D-Z, and a follow-up article will introduce us to the various beauties present in fancy coloured diamonds.

One key factor to note is that size does make a difference to a diamond’s colour — the bigger the diamond, the more obvious its colour. The differences can be subtle, but they can cause dramatic variations in price.

Graphical diamond colour grade chart | Facets Singapore

Diamond Colour Scale

Colour usually manifests itself in a diamond as a shade of yellow or brown. This is why a diamond’s colour grade is based on its lack of colour rather than it’s apparent colour. Facets Singapore offers the entire range of (grades D-Z) diamonds for both our trade customers as well as diamond connoisseurs. To ensure that any natural colour present is typically undetectable to the unaided eye, aim for diamonds in the colourless and near-colourless range.

Physical representation of diamond colour in the GIA D-Z range | Facets Singapore

A physical representation of diamond colour in the normal D-Z range


Fluorescence and Diamond Colour

Fluorescence and Diamond Colour | Facets Singapore

Many diamonds emit a visible light called fluorescence when they’re exposed to ultraviolet (UV) radiation. Although invisible to the human eye, UV radiation is ubiquitous. Sunlight contains it and fluorescent lights emit it too. Naturally, approximately 30–40% of all diamonds have a level of fluorescence inherent to them. Blue is the most common colour of fluorescence in gem-quality diamonds, but other less often seen colours include: white, yellow and orange! This means if you take your diamond to a night club with UV lighting, there is a good chance your medium- strong fluorescent diamond will glow on the dance floor, how cool?

See also: Our guide to Insights into the Diamond Industry

The GIA and other reputable labs grade diamond fluorescence using: None, faint, medium, strong & very strong. Although there is a cost benefit associated with buying diamonds with faint, medium and strong fluorescence, there is no scientific evidence that a fluorescence level of less than strong has any influence on perceived colour. This means that all things equal, a faint fluorescence diamond can be an attractive buy as it would be approximately 3–7 % cheaper than an equivalent ‘none’ fluorescence graded diamond.

Another secret, or rather, handy tip, is that strong blue fluorescence can make a light yellow diamond look closer to its colourless cousins in sunlight. Blue and yellow are colour opposites and tend to cancel each other out, so blue fluorescence masks the yellow colour. However, if the fluorescence is too strong it might make the stone look cloudy or ‘milky’, and that can lower the value of the diamond.

Key Takeaways
  • Of the 4Cs, colour is the second most important characteristic because the human eye detects brilliance first (diamond cut) and colour second.
  • The 'lesser' the colour, the higher the grade.
  • As a diamond’s colour grade improves, it’s price increases. However, at a certain point, the colour difference cannot be detected unless under magnification.
  • To maximise your budget, choose what’s called a ‘near-colourless’ diamond (grades G-H) because the naked eye will still not see traces of colour for these grades.
Do you need guidance from a trusted diamond dealer? Let’s take this conversation further.


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Nikhil H.

Written by Nikhil H.

Digital Creator | Founder of @csgo2asia | @northeastern & @startupInst Alumni |
Graduate from North Eastern University in Boston, this esports team owner is also an expert on certified diamonds. Trained at GIA, New York, Nikhil carries with him 5-years of experience in the diamond business and has a fresh, unconventional writing style that resonates with today's Gen Y and Z.

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