4Cs - Diamond Colour

Colour is an interesting attribute in diamonds. For when one thinks of the word ‘colour’, what usually comes to mind is the prevalence of bright, flashing tones; the sort of thing one tends to associate with gemstones in general, and with sapphires in particular. With brighter, vivid colours being the most sought after. In the world of diamonds, colour is significant for the opposite reasons. So whilst the importance of the gemstone’s glow, and its ability to reflect light (a key factor in the production of colour), is important, what matters in the context of diamonds is the absence of colour. Meaning the colourless character of diamonds is a key determinant of their value. For when one thinks of diamonds generally what comes to mind is their ‘white’, seemingly transparent character, one that glitters greatly in the presence of light. Simple as this characterization may be, it is not far from what determines the actual value of diamonds. The key addition being the factors that contribute to these characteristics varying from diamond to diamond; which in turn are determined by the 4Cs of diamonds. Here we will outline the key points you need to know when it comes to diamond colours: How a diamond’s colour corresponds to its value; the differences between diamond colours, (or colour shades) and intro coloured (fancy) diamonds.

The GIA Scale

The GIA (Gemological Institute of America) grades diamonds on a scale of D (colourless) through Z (light colour). Diamonds that fall into the D-Z range are considered to be within the “colourless” range, despite the variants that fall further from the D type containing varying levels of light colour tones. The presence of colour is viewed in a negative correlation with the diamond’s value. Fancy coloured diamonds are diamonds that contain distinct colours like yellow, pink, and blue, and are graded on a separate colour scale. Here we will break down the colour categories that group colourless diamonds: going from the colourless to the ones that contain more colour, and less value. When it comes to purchasing a top-quality diamond one must consider the relationship between the quality of the diamond in relation to its colour (i.e. its absence) and the price it commands. In going for a top-quality diamond, that is also affordable, it may not always be an optimal decision to choose a colourless one. As diamonds that have a stronger tint tend to have the benefit of a larger carat, be cheaper and of better cut. However some buyers will always opt for quality over price, whilst others may find themselves somewhere in between. The GIA scale provides a helpful framework for understanding the value of diamonds in relation to the presence of colour. This brings us to the subject of the types of diamonds, as diamonds depending on their various characteristics, in this case, colour, vary in important ways. 

Colourless

Completely colourless diamonds that fall into the D-F range are considered colourless diamonds. Naturally, these are the rarest, and hence also command the highest prices. With diamonds that hold the status of ‘D’ being classed as white diamonds. Such precious stones are extremely rare, and pricey. In the market for diamonds, it is realistic to find a carbon-based gemstone that falls within the E and F ranges.

Nearly Colourless

Diamonds that fall into the G, H, I, and J range are knowns as nearly colourless diamonds. The colour content for diamonds in this range is extremely small, and hence it is almost impossible to detect such differences without the aid of special tools. Despite the notable similarities in colour between colourless and nearly colourless diamond, the market price varies considerably between these two variants. With the nearly colourless diamonds costing nearly half the price of their colourless counterparts. So the price competitive character of diamonds of this range, along with their nearly identical character to actual diamonds, makes them a highly sought after choice.

Faintly Tinted

The diamonds that fall into the K-L-M range are considered faintly tinted diamonds. The ‘tint’ in this context refers to the prevalence of a shade of yellow-to brown shade. Its presence at increasing levels naturally affects the colourless, transparent character that is desired in diamonds; and also, problematically induces a level of translucence, affecting the diamond’s clarity. However the presence of such, for the most part, undesirable tint, is mitigated by the relatively lower levels of such a tone that is found in this range. Hence the term ‘faintly tinted’. From a value standpoint, tinted diamonds that fall into this particular range are a very good option since the yellow tint is extremely faint, and the prevalence of this tone can be balanced by a larger carat diamond: since the lower relatively lower colour quality would reduce the price of the stone overall, thus enabling the purchase of a larger diamond.

Lightly Tinted

So now we are getting into the higher colour/tint, and thus the lower value range. Lightly tinted diamonds are a category of carbon-based precious stones that fall into the N-O-P-Q-R range. The term ‘light’ implies that the yellow colour tone is stronger in this range, with some gemstones at the lower range containing a darker tone, that is closer to brown. This is not a favourable quality in colourless diamonds, and the prices of diamonds that are found in this range being markedly lower than those above. With the colour in this category of diamonds quite being quite visible to the naked eye.

The Real vs Apparent Colour of Diamonds

In addition to the colour of diamonds, depending on the stone, being hard to detect with the naked eye, the colour present in a diamond often depends on the lighting conditions under which it is observed. The role played by the external environment, either the type of light or lights under which the gemstone is studied, or the jewellery setting in which it is placed; these factors necessarily affect, not actual, but the perceived colour of the stone. As noted, the differences between colourless and nearly colourless diamonds are minimal, but yet significant. However, determining their character will often require expert study. In relation to this, a diamond that falls into the nearly colourless range can seem more like a diamond from the colourless range, depending on the lighting conditions in which it is placed. Or the type of metal band (in the case of engagement rings) the stone is set in.

Since the differences between diamond ranges in relation to colour is often quite small, the importance of the ‘C’ colour, must be viewed in relation to the others: The carat, cut and clarity of the stone all have a considerable effect on the stone’s quality, including its colour. For example, a larger carat diamond will have a larger physical presence, and hence its colour is likely to be more visible, which may artificially accentuate its tone, depending on the lighting condition.

When it comes to seeking expert advice on diamond colours, and later when purchasing diamonds of your choice, it is important to learn about the colour grading process adopted by your gem merchant or jeweller. The right process of grading colour in diamonds involves studying them in environments with neutral colours (colours that don’t appear in the colour wheel), such as those with lower saturation: brown (light), grey, white. This is important since diamonds are extremely good at absorbing light but do so selectively. Thus the use of neutral coloured environments, with no presence of secondary sources of strong colours, is required for assessing the true colour of diamonds.

Diamond Fluorescence

Certain diamonds have contained a quality called fluorescence. Fluorescence in diamonds refers to the ability of the gemstone to emit a certain (often) bluish tint, which often, depending on the colour grade of the stone, produces a milky tone. Fluorescence is not a universal quality in diamonds with only a third of diamonds carrying this quality, which in turn depends on the level of fluorescence, which varies depending on the diamond in question. Going further, the kind of fluorescence differs not only interns of its strength (i.e. very milky – light milky tint), but also in different types of shading: such as oily tone. Diamond fluorescence is an interesting and often conflicting subject when it comes to the study of diamond quality. For despite being viewed as an unfavourable factor in high-quality diamonds (colourless); fluorescence is viewed as an advantage in diamonds with a stronger (yellowish to brown) tint. Since the fluorescence adds a bluish tint, which is viewed as attractive. Something akin to blue diamonds. This brings us to the subject of fancy coloured diamonds.

Fancy Coloured Diamonds

The reader must understand that the subject of fancy coloured diamonds is a vast area, involving diamonds that contain natural colour, with blue diamonds arguably being the most popular variant. The factors that lead to the emergence of coloured diamonds; their strengths and weaknesses; the factors that contribute to their rarity and value. Whilst the concept of “fancy” coloured diamond might seem like a fancy subject that preoccupies the interest of certain niche groups in the world of gems and fine jewellery. Not actually. Fancy diamonds are highly valued precious stones, possibly the most expensive, and have in turn given rise to a specialized industry that exists to service this high-end market.