Complete Guide to Diamond Color February 26, 2019 – Posted in: Jewelry Blog
To any casual observer, diamonds have no color. In most cases, to any untrained – and disinterested – eye, they will look like clear glass.
However, if a diamond truly is clear, or colorless in diamond terms, then it is a rare diamond indeed. The vast majority of diamonds have at least a faint hint of color. In the main this color will be yellow. There is a point where a hint of color in an otherwise colorless diamond becomes an actual colored diamond. These “fancy” diamonds are not a part of the diamond scale we use when establishing the color grade of a diamond.
Where The Diamond Color Scale Comes From
Until the scale was standardized by the Gemological Institute of America (GIA), there were several different color scales in use. Although the GIA scale is not official in any legislative capacity, it is the scale to which most diamond assessors defer.
Before GIA, diamond scales would be I, II, III etc, A, AA, AAA. The problem with these scales is that they don’t really offer any true indication of diamond color across a wide range of examples. To rectify this, GIA established a scale which began at D and ended at Z. In the scale, D is colorless, and Z is a diamond with light color. The highest grade is D because some previous scales had grades of A, B and C. GIA wanted a clean break with the past and to avoid further confusion with overlapping terminology.
Although color grades go all the way to Z, in practical terms many dealers will not stock diamonds at the lower end of the scale.
The D to Z of Diamond Color
Diamonds of all sizes and colors are rare. But diamonds which are truly colorless are extremely rare indeed. This makes them very valuable and very collectible. These diamonds achieve the grade of D on the color scale and, assuming other factors are equally high on their own scales, will be very expensive even at small sizes.
As the scale progresses, each grade indicates an increasing level of color. Without a reference diamond to compare the subject stone against, any color can be difficult to see. In fact, to all but a diamond expert, color will be impossible to see until quite a way down the scale.
Only when we get to the K color grade do we mere mortals have a chance of spotting color in a diamond without anything to compare it to. Even then it will be by no means obvious, and it may be several further grades down before we genuinely see a hint of yellow in the diamond.
To learn more about each color grade, feel free to read our articles.
How The Diamond Color Scale Is Structured
Although there are 23 color grades on the scale, GIA sub-divide the scale into five distinct sections. Between D and F color, these are colorless. G to J are near-colorless, K to M are faint, N to S are very light and T to Z are light. Certainly by M color, the yellow tint will be fairly obvious to anybody with normal color vision.
Throughout the scale, the color referred to is exclusively yellow, although by the very lower end the color may appear more brown than yellow. All other diamond colors don’t have such a wide range of tints. Most will be a single color or have a primary and secondary color such as red as the primary color and blue as the secondary. In either case, though, the color will be obvious. It may vary in shade and richness slightly, but it is definitely a colored stone, and not a colorless stone with a hint of color.
K Color Diamonds and Beyond
Between D and J color, we consider these diamonds to be colorless or near-colorless. Consequently they will suit any metal setting, whether white metals such as platinum, or yellow gold. Once we get to K color and beyond, the increasing yellow in the diamond can affect how the stone looks in a white metal setting. Any yellow hints are exaggerated by the contrast of the metal and the diamond. This may not be desirable to some buyers. However those diamonds, when set in yellow gold, can take on a very pleasing and attractive warmth which would otherwise not be apparent.
This yellow gold effect means that there is a market for diamonds further down the color scale than there might otherwise be. Many jewelers will not stock diamonds beyond K color, in spite of the obvious market for them.
Fancy Colored Diamonds
Once we get past Z color, we get into fancy color territory. Diamonds can occur in a wide range of colors with yellow being the most common. Other colors are red, blue, green, purple, orange, pink and even black. All fancy colored diamonds, including yellow, are extremely rare. They are, in fact, far rarer than D color diamonds.
Although completely different in outward appearance, reason for the color aside, every diamond is identical in structure and composition. Each individual color occurs for one of a number of reasons. Colorless diamonds are as pure as a diamond gets, with absolutely no other minerals or trace elements in the crystal structure.
The common yellow color is caused by the presence of trace volumes of nitrogen. Nitrogen particles absorb blue light, and so light entering the diamond gets reflected without the blue, making it appear yellow. In other cases, different trace elements perform a similar absorption of one or more parts of the light spectrum to create the resulting diamond color. Blue diamonds, for example, contain boron. Black diamonds have a combination of physical flaws and particles of graphite. Together, these prevent all light escaping and thereby creating the black color.
Red and pink diamonds are caused by the crystal undergoing plastic deformation during its formation. When the crystal is growing, atoms can become displaced. This then creates the color as the diamond undergoes huge pressures in the earth’s crust. This phenomenon is so rare, that the largest red diamond in existence is only 5.11 carats in size. Red diamonds cost more per carat than any other color. Prices often run into the hundred of thousands of dollars per carat range.
Click here to learn more about colored diamonds.
Investing in Diamonds
Only the very best diamonds are a worthwhile investment. Even then, it can take years to realize any kind of profit on a purchase. Fancy colored diamonds are the best investment opportunity. These are usually bought by collectors at auction, and few make it to the open market. The exception to this is fancy yellow diamonds.
Even the best D color, flawless clarity diamond will struggle to turn a profit, unless of exceptional size. The key is remembering that any dealer can buy diamonds at half the price they charge to buyers. So, if you buy at retail prices, it can be decades before a diamond even gets back to its purchase price.