What comes to your mind when you think of diamond colors? Some people see diamonds as expensive rocks, while others see them as crystal-clear sparkly rocks.

And since clarity is among the main factors that determine the value of a diamond, it is unusual to settle for anything short of perfect colorless stone. That’s the case, especially if you’re purchasing a “fancy diamond.”

Fancy-colored diamonds are what people refer to any diamond that is not part of the normal color range of light brown to light yellow.

All diamonds fall within a color scale that ranges from D to Z. Diamonds within this range will decrease in value as their color becomes more obvious. The opposite will happen when it comes to fancy diamonds: if the diamond has a vibrant color the more valuable it is. Any color that is not within the Z range is regarded as “fancy” and is valued as such.

Most people are probably accustomed to pink, yellow, and black fancy diamond colors, but today we’re more concerned about the rarer ones like purple, red, and green. While colored diamonds are still regarded as diamonds in composition, they have slight defects. Each color is caused by the deformation of a different atomic that makes the stone has a unique color. And since these deformations do not occur regularly, fancy diamonds are extremely rare and are usually sold at a higher price.

Below you’ll learn what causes the fancy diamond color, and why they are so rare.

Red diamonds are special. They are not only the rarest diamond color but also the most expensive diamond in the world. They are formed when the diamond crystal lattice deforms in a process known as plastic deformation. 

A bruise is formed when the lattice gets twisted. What we see as red with our naked eyes is a result of light passing through this deformation.

The process of a pink diamond formation is essentially the same as that of red diamonds, where the plastic deformation in the diamond occurs due to stress within the Earth.

When the light transmission passing through the stone is really strong, a red diamond is created. However, the light transmission is normally weak, making the diamond turn pink.

Primarily, green diamonds are a result of exposure to radiation. Just like other color diamonds, the lattice becomes deformed when the diamond comes into contact with radiation, and carbon atoms are replaced. As opposed to red or pink diamonds, the stone transmits green hues after absorbing the reddish light.

These are the most common diamond color after brown diamonds. The yellow color is formed when the nitrogen atoms are substituted for carbon in the diamond’s crystal lattice. As a result, blue light is slightly absorbed and is transmitted as yellow.

While it’s still unclear how exactly purple diamonds are formed, in most cases, the stone contains hydrogen at the center, alongside plastic deformation. They are the second rarest color after red.

By now, you’ve probably realized that rare diamond color is usually as a result of crystal lattice alteration of the stone. Blue diamonds are not different.

In this case, the boron atoms cause a blue transmission when they work their way into the crystal lattice and knocks out carbon atoms. The blue color is transmitted after the absorption of the red light.

The formation of black diamonds occurs when a huge amount of mineral inclusions reduces the amount of light that passes through the stone. Black diamond is unique, with even notable figures such as Carrie Bradshaw using it as an engagement ring.

Brown diamonds are not as rare as other fancy colors. It is also formed through plastic deformation, which occurs when carbon atoms within the stone are replaced. Most diamonds are within the yellow-to-brown range.

It’s very difficult, if not impossible, to grade a diamond’s color just by looking at it. The reflections and sparkle make it challenging to notice color differences. This explains why selecting a lower color grade in rings could be a good compromise.

Having said that, you can best view the grading from the diamond side by comparing it to other diamonds.

There’s a lot to keep in mind when selecting the best diamond color. From the colorless to the colored to the grade. Be sure to consider your personal preference when choosing your diamond color.