Posted on January 08 2021
Diamond is a crystalline carbon, it’s known as the hardest mineral and considered a highly valuable precious stone.
Diamond color is an important feature that determines the value and price of such a precious stone and – even if they are largely known to be white/transparent stones - diamonds can actually come in a wide range of shades and colors.
Therefore, diamond colors have been standardized by the GIA (Gemological Institute of America) and IGI (International Gemological Institute). Both are renowned and large institutions and have top quality labs.
Both GIA and IGI classify diamond colors on a scale from D to Z, but while the GIA deals with the grading of natural diamonds, IGI uses a similar scale but for lab-grown diamonds.
In both cases, all the diamonds from D to Z are considered White Diamonds and they have a higher or lower tinge of yellow. Colored diamonds, such as vivid pink or green, are called Fancy Colored Diamonds and they are extremely rare and, therefore, highly valuable.
In this article, you are going to learn anything you need to know about diamond color and grading in detail as we aim to provide you with a complete and comprehensive knowledge about the subject.
What is Diamond Color due to?
Diamonds are made in the Mantle of the Earth - 100 miles underground. The extremely high levels of temperature and pressure can modify graphite (a crystalline carbon) on its atomic level. The graphite’s molecular composition changes and results in the sparkling, shiny, and extremely hard hexagonal sheet pattern that we know as diamonds.
This process doesn't happen overnight; it takes millions of years and, during such a long time, other chemicals can be trapped in the process. When this happens and those chemical impurities become a part of the structure of the diamond, it results in a higher or lower presence of color in the structure of the precious stone.
Only when the process remains free of impurities over the millennia, we have a colorless diamond. Now, you can understand why white diamonds are so rare and valuable.
The main impurity that can be “trapped” in the stone during its forming process is nitrogen (nitrogen atoms). When these atoms are present in a large number, they cause a tint in the diamond that can go from brown to yellow. When the nitrogen atoms are dispersed throughout the crystal in isolated sites, the diamond takes an intense yellow or brown shade.
How does the GIA and IGI grade the color of diamonds?
The difference between color grades in the standard scale isn't visible to the naked eye. An expert could look at the stone and tell whether it's colorless or nearly colorless, but no one is able to assign a specific grade on the scale by only watching at the diamond.
So, how are diamond colors graded?
At the GIA lab, the grading is made for comparison with master stones. Those master stones are aligned in a row from D to Z and located under a special neutral light that doesn’t affect the color of the diamond.
Then, a gemologist would place the subject diamonds between two stones and evaluate if it's better or worse than the surrounding ones. They would move that diamond up or down through the row until they find the point where the subject stone is between one that's better (less color – on its left) and one that is worse (more color – on its right). The diamond is assigned the grade of the master stone on the right.
The same process is repeated by several gemologists who are always unaware of the grade their colleagues have assigned to the stones.
The Standard Diamond Color Scale for White Diamonds
As we've mentioned, white diamonds are classified from D to Z, with D being colorless and Z having the highest tinge of yellow (as you’ll learn, they are called light yellow diamonds).
In a White Diamond, the presence of a yellow tint always lowers its price. Therefore, if we refer to the standard scale, D-graded diamonds are the highest valuable White Diamonds and the ones that better reflect light and their true color (which is actually the absence of color); while the Z-graded diamonds are the lowest priced.
D to F graded diamonds are considered - and called - Colorless Diamonds. It's hard - nearly impossible - to pinpoint them to the naked eye. A gemologist identifies them by comparing them to other graded diamonds (see the description of the process above).
What the naked and untrained eye can see is sometimes a sort of “distraction” when looking at the stone. When we look at a White Diamond, we always expect to see the stone shiny and sparkling. When the stone doesn't shine and sparkle as expected, that may be because they aren't D-graded diamonds.
They are the rarest and most expensive among diamonds. They lack any tint of color and are 100% colorless. They reflect the light and sparkle like no other stone on the planet and they are extremely attractive to the eye.
E diamonds are also considered colorless since the color in them isn't visible to the naked eye. They are also extremely rare (less than 1% of the diamonds present on the planet) and very expensive, but their price would be slightly lower than D-graded diamonds because of that low tinge of color in them.
In the range of Colorless Diamonds, F-graded ones are the lower quality. However, they are still considered colorless and therefore extremely valuable. For this reason, they can provide the best balance between the highest quality and value for money.
D, E, and F graded diamond would look extremely similar to the naked eye. To an untrained and unexpert eye, in fact, they’d look absolutely identical. When the presence of color is measured with an electronic colorimeter, the score of D diamonds would be 0.00 (complete lack of color) and the one for F diamonds would be a maximum of only 1.49.
Why should you purchase colorless white diamonds?
Despite diamond color isn’t the only factor that affects the quality and value of the stone (see below for details), it’s certainly one of the most important. Colorless Diamonds are so rare that they can be considered unique.
So, the answer to our question is: if you want something that – other than precious - is also unique, and if you have a high budget at your disposal, this is when you may want to purchase a colorless diamond.
Near Colorless Diamonds
In the standard GIA scale, diamonds graded from G to J are called Near Colorless Diamonds. They have traces of color, even though very tiny, that an expert gemologist could spot them to the naked eye. For untrained eyes, instead, it’s still hard to distinguish between Colorless and Near Colorless Diamonds.
If you are a complete beginner, however, one of the most efficient ways of telling whether a diamond is Colorless or Nearly Colorless is to check its price tag. Being less rare than Colorless Diamonds (they represent 15% of all diamonds in the world) and considered less valuable, Near Colorless Diamonds’ price is lower than Colorless ones (between 10% and 15% lower) but still higher than Faint Diamonds that we’ll describe below.
G to J graded diamonds still look very shiny and sparkling, reflecting the light beautifully with only minor sparkle distractions.
It's important for you to understand that you won't see or notice any yellowish shade on diamonds of these grades. The only thing you could spot, if your eyes are trained enough, is the diamond being slightly less sparkling or bright than a colorless diamond. You could start seeing a slight yellow tinge only on I or J graded diamonds and – because of this – there's a big difference between G/H diamonds and I/J ones.
When the presence of color in near colorless diamonds is measured with an electronic colorimeter, the score would be 1.50 to 2.49 for G and H graded stones, and 2.50 to 3.49 for I and J graded ones.
Why should you purchase a near colorless diamond?
Unless you are an expert gemologist yourself, you'll hardly spot that slight presence of color in your gem. For this reason, purchasing Near Colorless Diamond means choosing a high-quality majestic precious stone but to save some money which you can maybe invest in other features of the stone, such as cut or dimension.
Faint yellow diamonds
Diamonds from K to M grade are known as Faint Yellow Diamonds because they tend to have a faint brown or yellow shade.
It's important for you to know here that - if the tinge is visible to the naked eye on bigger stones - it will be hardly noticeable on little diamonds such as those mounted on pieces of jewelry. This is something you may want to consider, especially when you want to make a special gift or buy an engagement ring, but you're on a budget.
Faint Yellow Diamonds’ prices decrease a lot when compared to gems of higher grades because this is the level at which even an untrained naked eye can start spotting some color in the shade of the diamond.
The electronic colorimeter would measure a score that goes from 3 to 4.9.
Why should you buy a faint yellow diamond?
Diamond color isn't the only factor that determines a diamond’s value, but if you want to stick with the colorless appearance, K to M graded can still look like they have no tinge whatsoever if the stone is little like the ones mounted on the vast majority of jewelry.
Purchasing a Faint Yellow Diamond could be a chance of having a bigger stone with the same budget and you could also obtain a better cut.
The cut is important in the look of the stone at least as much as the diamond color (details in the dedicated paragraph): it affects the way the stone reflects the light, so a faint yellow diamond with a good cut can appear as sparkling and shiny as you’d expect a diamond to be.
Very Light Yellow Diamonds and Light Yellow Diamonds
Diamonds graded from N to R are called Very Light Yellow Diamonds. As their name suggests, in these diamonds a very light yellow coloration is visible.
In Light Yellow Diamonds (from S to Z in the GIA standard scale), instead, the yellow tint is more visible.
In both cases, however, the yellow tint is well visible but still very light. Do not expect to see a bright yellow stone if you purchase a Z graded diamond: keep in mind that, after all, we're still speaking of White Diamonds.
The reference points on the electronic colorimeter for these categories of diamond colors are:
- A score of 5 to 6.9 for Very Light Diamonds
- A score of 7 to 10 for Light Yellow Diamonds.
Very Light Yellow and Light Yellow Diamonds are all considered the less valuable among White Diamonds. Some stores or marketers don't sell diamonds under the L or H grade.
Fancy Colored Diamonds
So far we've talked of yellow and brown tins but we were actually only referring to White Diamonds.
A lot of people don't know that colored diamonds even exist. But they do exist, even though they are extremely rare: when a diamond shows a color even more intense than grade Z, or if it exhibits a color different from the above mentioned yellow and brown, it is considered a Fancy Diamond. Blue, orange, green, pink... very rare diamonds can be of all these beautiful colors.
Fancy diamonds are graded using a different scale. While the GIA under scale only indicates the presence of the color, systems for Fancy Diamonds need to be referred to both the presence and the characteristic of the color.
Fancy Diamonds Color Systems
The system with which labs classify gem colors consists of 27 color hues and nine saturation descriptors. So, for example, a Fancy Diamond can be classified as a “fancy intense blue diamond”.
In particular, the 27 color hues are Red, Orangish-Red, Reddish-Orange, orange, Yellowish-Orange, Yellow-Orange, Orange-Yellow, Orangish-Yellow, Yellow, Greenish-Yellow, Green-Yellow, Yellow-Green, Yellowish-Green, Green, Bluish-Green, Blue-Green, Green-Blue, Greenish-Blue, Blue, Violetish-Blue, Bluish-Violet, Violet, Purple, Reddish-Purple, Red-Purple, Purple-Red, and Purplish-Red.
However, for diamonds, additional colors can also be used: black (opaque), white (milky) gray, pink, and brown.
The 9 descriptors indicate the saturation of the color, that is how much the color of the stone is vivid, and they are the following: Faint, Very Light, Light, Fancy Light, Fancy, Fancy Dark, Fancy Intense, Fancy Deep, Fancy Vivid.
Are Fancy Diamonds Valuable?
When we spoke about White Diamonds, we claimed that D- diamonds are the most valuable because they are the rarest. To understand the value of fancy colored diamonds, then, you need to know that colored diamonds are even rarer than colorless ones: only 0.01% of diamonds have a color different from a yellow or brown.
Some colors are even rarer than others: red stones, for example, are the absolute rarest and, for this reason, the absolute most valuable.
The value of Fancy Colored Diamonds can be also affected by other factors such as fashion trends and popularity so that, for example, in certain periods pink stones were valued higher than blue ones, or the other way around, depending on the interest of the market at that specific historical moment.
Are you wondering what diamond color is the most expensive stone ever sold? In 2017, a 59.60-carat pink diamond, known as the Pink Star, was sold for 71.2 million dollars. It's the highest price ever paid for a diamond of any color.
What factors determine the price of the stone other than diamond color?
As we've already mentioned a couple of times, diamond color isn't the only factor that determines its value, and therefore price.
In fact, the guidelines used to determine diamond value are known as the four Cs, and the diamond color is only one of them. So, what do those other Cs stand for?
- Carat. The carat is the unit of choice to measure the weight of a diamond: 1 carat is 200 mg. Of course, the higher the weight of the diamond the higher the price. Decimals of the carat are also used in the standardized systems, so you can have, for example, a 0.50 carat diamond.
- Clarity. With the term clarity, we refer to the diamond’s purity which is not to be confused with the presence of chemical impurities that can determine the presence of color in a white diamond.
Clarity is determined by the presence or absence of inclusions ( those in the internal structure of the stone) and blemishes (external marks).
Diamonds are therefore classified as: flawless, internally flawless, very slightly included, slightly included, and included.
The greatest the clarity, the higher the value and price of the stone.
- Cut. The look of a diamond - its brilliance and therefore its value - depends a lot on the ability of the craftsman who cuts it. The way the stone is cut determines how it'll reflect light and how light interacts with every corner and surface of the stone.
The quality of the cat is valued considering 3 optical effects:
- brightness: the internal and external white light reflection
- fire: the scattering of white light into the colors of the rainbow
- scintillation: the amount of sparkles the diamond produces with the pattern of dark and light areas caused by the reflection within the diamond itself.
Is a D-graded White Diamond Always Preferable?
A D-graded diamond is the most valuable among White Diamonds, but this doesn't mean that you necessarily have to opt for that diamond color in particular when you purchase your stone for a special occasion.
If you - and the gift recipient - will hardly be able to spot the difference between D/E graded diamond and a G one, your wallet will certainly notice the difference.
A G diamond with an excellent cut can look just as gorgeous as a higher graded one: it won't show any yellow tint visible to the naked eye, and it would reflect the light beautifully. Plus, opting for a G diamond instead of a D or E one can make you save thousands of dollars.
Diamond color: Fluorescence
What is fluorescence? Diamonds’ fluorescence is the stone's reaction to UV light and it can affect the appearance of the stone itself. It is therefore an important factor to consider when discussing diamond color. Fluorescence usually reduces the price of the diamond, but does it mean that you should always avoid it?
It's very rare, but in Colorless and Near Colorless Diamonds, fluorescence can give a whitish or grayish tint to the stone. Therefore, when purchasing D to G graded white diamonds you should opt for zero or only faint fluorescence.
It's more common to see fluorescence having an impact on the diamond color on the Faint Light Yellow and Light Yellow Stone. In this case, however, the effect on the stone can be positive: can we make the stone appear whiter.
For this reason, when purchasing an I to L diamond, you may want to consider a medium or even strong fluorescence.
Diamond color: shape matters
As shape has an important role in determining how a stone reflects the light, it can also impact the diamond color.
Some shapes show more color than others. Take a look at the following list to understand the shapes that better reveal the stone's true color (in the first positions) and the ones that, on the contrary, can mask it better (on the bottom of the list).
- more crazy
Size is also an important factor that affects the way diamonds color is more shown or masked. Bigger diamonds reveal their true color in a better way while smaller ones can mask it better.
Diamond color: the jewelry metal
When selecting your diamond color, the metal of the jewelry it will be mounted on plays an important role. A Faint Light Yellow diamond could appear as white on a yellow golden engagement ring, while - on the contrary- a white border frame would make it appear even more yellow.
Diamond color is a complex subject. You may have spent some time reading our article and providing yourself with the proper knowledge, but at least now you know that you don't have to spend a fortune to purchase the perfect looking White Diamond.
Your knowledge about White and Fancy diamonds may have now changed as well as your appreciation for the rarity and beauty of these stones that take ages to be formed, ages to come to light from the depth of our Earth, and that carry value, meaning, charm that go way beyond the atoms they are made from.