D colour diamonds

D Colour Diamond

A ‘D colour’ is the best colour of diamond you can get and these icy white stones represent just a tiny fraction of the diamonds mined every year. They are highly prized by the top jewellery designers and houses worldwide, who use them for their signature pieces. So, what's so special about D colour diamonds, where do they come from, and should you get one?

Diamond colour

One of the ways in which the quality of a diamond is assessed is its colour. While diamonds come in a whole range of colours, normally when we are talking about diamond colour we mean how colourless or yellow a diamond is. Other colours, such as pink, blue, or green are known as ‘fancy’ colours and have their own scales on which their colour saturation is graded.

The other grading criteria for diamonds are carat (size), cut (shape), and clarity, and collectively these are known as the 4Cs

A diamond is given a colour grade on a scale and this is communicated on a diamond certificate by a letter and helps to determine its value. The whiter or more ‘colourless’ the diamond is, the higher the price it will be, assuming that all the other Cs are equal.

The scale goes from D, ‘colourless’, to Z, yellow. Grades D to F are regarded as colourless grades. Grades G, H, I, and J are considered near colourless. K, L, and M are classed as faintly coloured. N-R are said to have a very light colour, and S-Z as having ‘light colour’.

It is generally accepted that colour in a stone becomes noticeable, without having to inspect the diamond under magnification, at grades J/K. A diamond's colour is graded by comparing it to a set of control stones in a lab, under 10x magnification.

The two main diamond grading laboratories are the GIA and IGI, who have experts in labs all over the world who grade diamonds and produce certificates. Of the two, the GIA is regarded as the most reliable and rigorous by the jewellery industry, and stones of the same quality with a GIA cert will often be priced slightly higher than those graded by the IGI.

Why does the scale stop at D?

The scale that we use for grading diamonds today was standardised by the GIA in the early 1950s, and stops at D in case diamonds with even less colour are ever found.

Why do some diamonds have different colours than others?

Diamonds have (or don’t have) colour because of chemical impurities in their atomic structure or because of a distortion of that structure that occurred as the diamond formed.

Diamonds are made from carbon, though other elements can become trapped inside when the diamonds form, and it is these that cause the stones to reflect and absorb different wavelengths of light, meaning they appear to be different colours.

A diamond made purely from carbon will be colourless, while those that contain some nitrogen atoms will be yellow. It is very rare for a diamond to contain no nitrogen at all and these diamonds are considered truly colourless, though, it may be impossible to differentiate a diamond that contains a tiny amount of nitrogen from a diamond that contains no nitrogen and both could be graded as a D colour.

Traces of the element boron will make a diamond blue, whilst fancy grey and violet diamonds contain hydrogen, and green diamonds are those that have been exposed to natural radiation when they were formed.

Where do D colour diamonds come from?

D colour diamonds can be found in mines all over the world, though some locations are known for producing different types of diamonds and this can be for a variety of reasons. Namibia, in southwest Africa, is known for producing some of the finest diamonds in the world. This is because of the journey that these stones take from where they have formed to where they are mined.

Of the diamonds found in Namibia and off its coast, a large proportion have high grades for both colour and clarity. This is because the stones there have already travelled a long way when they are found by people. The original source of these diamonds is thought to be kimberlite pipes in central southern Africa, some 300 miles to the east of where they are found today.

This means that they have travelled from this location by the power of water and this process means that diamond crystals with more imperfections, which make them more fragile, are more likely to have been broken apart as they have been tossed around over the course of millions of years.

Ethical D colour diamonds

As luck would have it, Namibia is one of the best places to buy diamonds from an ethical point of view. The country's diamonds are mined and sold by Namdeb, a company owned half by the Namibian government and half by De Beers.

Unlike other African countries, there is no history of Namibian diamonds funding conflict and the high standards of governance and relatively high standard of living for the region means that the jobs the company provides are high quality and well paid.

Does diamond colour affect sparkle?

No. Colour and clarity are different factors that don’t really overlap. The only time they do is when you get down to the very lowest end of the clarity spectrum, where a stone is so full of inclusions that it might make it hard to identify the colour or completely fill the stone with inclusions like the example of black diamonds.

The sparkle of a diamond is determined mostly by the way the stone is cut and the stone’s clarity.

Should I get a D colour diamond?

Whether you choose to buy a D colour diamond is up to you and almost entirely based on your personal preference. The only objective advantage is when you reach the very top end of the diamond market. In this case, going for the best grades is always helpful and gives you the best chance of making a large profit on an investment diamond.

For most of us, there will be something of a trade-off between size and colour, and the quality factors in as well, in order to get a stone that we love within a certain budget. This may mean that you can get a D colour stone with a lower clarity grade in order to get a stone as big as you originally hoped.

Natural D colour diamonds do come at a premium, as their rarity means they will always be in limited supply.

Is it better to get a diamond with good colour or one with good clarity?

Again, this is subjective, but, at a glance, I think that it is easier to notice the colour of a stone than the clarity, especially when you get to the higher clarity grades. You won't be able to pick out a small inclusion inside a diamond when it's set in a ring and being worn on a finger. However, you might be able to notice if the whole stone has a slightly yellow tint.

Inclusions in a diamond are only visible to the naked eye once you go below an SI1, so, if the choice is between an F colour VVS2 and a D colour SI1, then it might make sense to go for the slightly lower colour. This depends on the price difference as well as where the inclusion is and exactly what form these inclusions take.

Diamond colour and fluorescence

Around 1 in 3 diamonds has some level of natural fluorescence and whilst it is normally considered a negative, it can have some interesting effects on already colourless diamonds. Most diamonds that have fluorescence will fluoresce blue to different degrees, and this can help to cancel out any yellow in the stone and can actually help to make a stone appear whiter than it otherwise would.

A stone with very strong fluorescence might make a diamond appear slightly whiter under normal lighting conditions, though in most cases fluorescence in a diamond will not be noticeable under anything except strong UV lighting.

If all other quality factors were equal, fluorescence in stone D colour stone could bring its price down slightly compared to a stone without fluorescence.

Are D Colour diamonds rare?

Yes. Of all the diamonds mined every year, only around 30% are of gem quality. This means that they have characteristics such as size, colour, and clarity that allow them to be cut into gemstones. The other 70% are used industrially.

Of these 30%, less than 0.5% are D colour.

What is the best setting for a D colour diamond?

To bring out the colour of the diamond, it is recommended to have a white metal setting, such as white gold or platinum. Whilst diamonds don't absorb colour, if you set a stone in yellow or rose gold then some of the colour from that metal will be reflected.

This being said, if trends are for yellow or rose gold, then having a great quality diamond set into it will give you the best chance of it looking white. A D colour diamond set in yellow might look slightly yellow, but a G colour would look far more yellow.