Diamonds are graded on the GIA colour scale from D (colourless) to Z (light yellow). The most expensive diamonds are found at either end of the scale, due to their rarity. But don’t confuse rarity with beauty.
Colourless is rare. Highly coloured is rarer, and consequently, more valuable. Diamonds with a trace amount of colour are just as beautiful, but less rare, making them a better value. Most people, when shown a series of diamonds from D to Z, choose the G-H-I-J range.
If you're looking to buy fine diamond jewellery such as an engagement ring, it's important to understand how diamond colour affects the price. Here are a few buying tips and things to know about diamond colour.
When it comes to diamonds, less colour means higher quality. While brilliance is the first thing you notice about a diamond, colour is the second. The higher the colour grade, the less colour there is, and the more expensive it will be.
For the best value, choose G-J diamond colour grades in the Near Colourless category. With these diamonds, the naked eye can’t discern any colour. The visible difference between diamonds of one colour grade (G-H or I-J) is so minor it’s difficult to detect with the unaided eye, but the cost savings can be significant. Keep this in mind when choosing your diamond colour grade.
In general, to avoid a pale yellow colour, choose a diamond grade H or higher. For the purist, look for a D to F grade colourless diamond, which will have no discernible colour under magnification.
Diamond shape, size and your ring’s metal setting can visually impact diamond colour.
Ring Setting — Pairing diamonds with similar toned metals can neutralize colour in the diamond. Consider setting higher colour grade diamonds like Near Colorless diamonds (G-J) in yellow gold and Colorless diamonds (D-F) in white gold or platinum. A gold setting may show through a colourless diamond.
Diamond Shape — Some diamond shapes may show or mask colour to varying degrees. For example, brilliant-cut shapes such as round and princess reflect more light, which means more colour is masked. Step-cut diamonds (emerald and Asscher cuts) may show more colour because they are cut with fewer facets, resulting in bigger “windows” through which to see the colour.
Fancy shaped diamonds, like pear and marquise, may also show slightly more concentrated colour at their points.
Diamond Size — Color is easier to see in larger diamonds. If you want a diamond above 1 carat, choose a G or H coloured diamond. I-J colour diamonds are best when just under a carat.
White Diamonds Vs. Coloured Diamonds
When is colour a good thing? When it refers to the rainbow spectrum of colours – red, orange, yellow, green, blue, pink, purple, and more – that diamonds come in. These are known as Colored Diamonds. Only one in every 10,000 diamonds possess natural colour, and the more intense the colour, the more rare and valuable the diamond. Coloured Diamonds are graded on a separate diamond colour scale and can be even more valuable than white diamonds.