Color of a diamond is the second most significant factor to consider when you make a purchase. Diamonds are colored when the crystals grow inside the earth. Tiny traces of some elements like nitrogen can color the crystals. Diamonds that have higher concentration of nitrogen begin to develop yellow hue. Besides, the pressure involved in the diamond formation helps distortion in the crystal structure which is believed to also contribute to its color. It is very rare to find a diamond that doesn’t have any color at all. In fact, natural diamonds can be found in a huge range of colors, including grey, white, yellow, brown and pink.

The closer a diamond is to colorless, the rarer and more valuable it is. Diamond Color is graded in terms of how white or colorless a diamond is. The industry standard for diamond color grade is the scale established by The Gemological Institute of America (GIA), ranging from D to Z — D being completely colorless and Z being light yellow in color. The distinctions in color are so subtle as to be invisible to the naked eye. However, they do have an impact on the price and quality of the stone.

  • D grade diamonds are absolutely colorless and rarest of all.
  • E and F grade diamonds are also considered colorless. The grades, D, E, and F have little difference that only experts can see it unless they are set in the ring.
  • G, H, I and J diamonds are nearly colorless. 
  • K, L, and M grade diamonds are faintly tinted. Diamonds under 1/2 carat appear colorless when they are set in the ring. Diamonds over 1/2 carat may show a tint of color.
  • Diamonds graded N through Z have a visible light-yellow tint.

Why does GIA start their Color Grade from D?

There was no conclusive standard to define what diamond color is before GIA created the D-to-Z Color Grading Scale. A variety of other systems were used loosely, from A, B, and C (used without clear definition), to Arabic (0, 1, 2, 3) and Roman (I, II, III) numbers, to descriptive terms like “gem blue” or “blue white,” which are notorious for misinterpretation. So, the creators of the GIA Color Scale wanted to start fresh, without any association with earlier systems. Thus, the GIA scale starts at the letter D. Very few people still cling to other grading systems, and no other system has the clarity and universal acceptance of the GIA scale.

According to GIA, “The world’s first system for grading diamond color dates back to sixth-century India.” Little to no sort of standardized, methodical, and repeatable process was in place to accurately and consistently derive a color grade. What made this worse was that jewelers around the world in the trade would reference local, cultural, and descriptive terms that had widely varying meanings. Words like “no color”, “white”, “blue”, “yellow”, “canary yellow”, “A”, “AA”, or even “AAA” and similar repetitive alphabetical and numerical verbiage would confuse buyers and sellers. It wasn’t uncommon for one seller to expect that “canary yellow” was X color, while one buyer expected “canary yellow” to be Y color.