What Makes a Diamond "Fancy Color"
Fancy color diamonds fall outside the standard colorless-to-light-yellow D–Z range that most diamonds are graded on. The color is caused either by trace elements trapped in the stone as it formed, or by a structural distortion in the crystal lattice itself.
What Causes Each Color
- Yellow & orange: trace nitrogen atoms trapped in the crystal lattice as the diamond formed.
- Blue: trace boron. Blue diamonds are especially rare partly because boron is scarce in the deep mantle regions where diamonds grow in the first place.
- Pink & Red: not caused by a trace element at all. GIA's own research attributes roughly 99.5% of pink diamonds to a structural distortion called plastic deformation, where immense geological pressure permanently shifts the crystal lattice out of alignment, changing how light passes through the stone. Red diamonds share this same underlying cause in its most extreme form, and they're the rarest diamond color in the world — fewer than about 30 gem-quality natural red diamonds over a carat are known to exist anywhere, which is part of why GIA doesn't even use intensity grades below "Fancy Red" for the color.
- Green: natural exposure to background radiation in the earth over a very long period, sometimes combined with trace nitrogen, hydrogen, or nickel.
- Brown / Champagne: also plastic deformation — the same underlying mechanism as pink, producing a different visual result — often combined with nitrogen-related defects. We cover this in depth in our champagne diamonds post.
- Black: dense clusters of graphite or other mineral inclusions, rather than color from light interacting with the crystal itself.
The Fancy Color Grading Scale
Fancy colors are graded on intensity across nine levels: Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, Fancy Vivid, Fancy Dark, and Fancy Deep. It's a common misconception that this runs in a straight line from weakest to strongest — Fancy Dark and Fancy Deep actually describe specific darker tone-and-saturation combinations rather than simply "more intense than Vivid," so a stone can be extremely richly colored without technically being graded "Vivid."
Natural vs. Lab-Grown Fancy Colors
Natural fancy colors are exceptionally rare — only a small fraction of mined diamonds show fancy color at all — and priced accordingly; vivid natural pinks and blues rank among the most expensive diamonds in the world per carat.
Lab-grown fancy colors are produced a couple of different ways depending on the color. Blue and yellow are often achieved as-grown, by introducing trace boron or nitrogen during the HPHT growth process, though many CVD growers now deliberately exclude nitrogen when their goal is a colorless stone. Pink and red lab-grown diamonds are typically a different story — rather than growing colored, they're usually grown colorless and then treated afterward with irradiation and annealing (sometimes finished with a second HPHT step) to produce the color. Either way, lab-grown fancy colors sell for a fraction of natural fancy-color pricing, opening up a category that used to be reserved for auction houses. It's always worth asking whether a fancy color stone's color is natural, as-grown, or treated, since that affects both its price and how the color is described on its certificate.
Styling Fancy Colors
Yellow diamonds tend to glow brightest against white metal, where the contrast makes the color pop, or set in yellow gold for a rich, monochromatic look. Blue and pink diamonds are usually set as a solitaire or halo center stone specifically to let the color take center stage, often paired with white diamond accents for contrast.