How Pink Diamonds Are Formed And Get Their Color

The Princie fancy intense pink diamond set a $40 million price record in 2013.

There are a few things you probably knew about diamonds without doing any indepth research – that is, everybody knows that diamonds are the hardest substance on Earth and they are the most expensive gemstone in the world.

As you learn more about diamonds, you will probably come across four main characteristics that define a diamond’s quality. These characteristics are also known as the “four C’s” and are cut, carat, clarity and last, but not least, color.

When you study a little more about what we understand by diamond color, you will see that a “colorless” diamond is usually preferred in the consumer market.

So, if a diamond ought to be colorless, why do we still care about pink diamonds? Well, let us talk about what fancy colored diamonds are and how pink diamonds are formed.

What Are Fancy Colored Diamonds?

A diamond’s color is typically graded on a scale of D to Z, where D represents a colorless state and Z represents a yellowish/brownish hue. When a yellowish/brownish diamond’s hue is more intense than a Z colored masterstone, it will be classified as a “fancy color diamond”.

Likewise, when the diamond has a different hue (e.g. pink, blue, red etc…), it would be categorized as a fancy color diamond if the coloration is sufficiently intense.

Interestingly, diamond colors can range from pink, through green and magenta to whatever color you would see in the entire spectrum, and even black. As a result, this makes the usual grading system of D-Z incompatible.

Instead, a grading system similar to that used in emeralds or sapphires is applied. Instead of alphabets, descriptive words like “fancy light pink” are used to describe the diamond’s color.

GIA reference color chart for pink diamonds showing color transitions.

James Allen has a superb selection of GIA certified pink diamonds with different color hues, tones and saturation. Check them out for yourself to see how pink diamonds look like in real life.

How Are Diamonds Created in Nature?

If you had watched the movie, Superman, you would probably remember seeing him turn pieces of coal into diamonds using his hands. Well, that is just science fiction.

First of all, pieces of coal cannot be simply crushed and transformed into diamonds under high pressure forces. Secondly, the “raw material” for making diamonds are carbon deposits that are older and existed before any known vegetation responsible for today’s source of coal.

Diamonds are formed deep in the Earth’s mantle under extreme conditions which require a specific range of temperature and pressure. After formation, the rough diamonds are brought to the Earth’s surface by violent volcanic eruptions via kimberlite pipes where they are usually mined.

How Do Diamonds Get Their Color?

How a pink diamond looks when it is unpolished. Credits: GIA

There are a number of reasons that cause a diamond to display a certain color. The most common reason for coloration is due to the presence of trace elements in the diamond’s chemical composition.

For example, traces of nitrogen in a diamond’s composition give it a strong yellowish color. And since nitrogen is everywhere in Earth’s environment, most of the diamonds that are mined tend to be yellowish in color.

The presence of radiation sources during the formation process can permanently alter the diamond’s hue – usually yielding a greenish color. On the other hand, black diamonds are the result of severe graphite and iron inclusions which turn the diamond completely opaque.

What Makes Diamonds Pink And How Are They Formed?

1.09 carat fancy purplish pink diamond that costs $685,000.

While most other colored diamonds already had their origins and causes of color scientifically explained, one mystery that still puzzles scientists today is the origin of pink coloration in diamonds.

Around the world, pink diamonds can only be found at certain mines. Most notably, Australia’s Argyle mine is well known for producing rough diamonds with fantastic shades of pink (and prices too!). It is believed that pink diamonds didn’t start their growth process as pink.

Instead, scientists speculate that the stress and strain experienced by rough diamonds when they are in the Earth’s mantle causes the diamond’s lattice to be distorted. This distortion creates graining and causes pink color zones to occur within the diamond.

Despite the sophisticated lab analysis equipment available to scientists at the time of writing, no one has completely cracked the code on the mysterious color centers that induce pink hues in diamonds.

How Are Pink Diamonds Grown in the Laboratory?

1.59 carat fancy pink cushion lab created diamond that costs $11,650.

Natural pink diamonds are very rare and they usually command astronomical prices. As a result, there are treatments and manufacturing processes that are used to artificially create pink diamonds at significantly lower costs.

Synthesizing diamonds in the lab is nothing new and methods like chemical vapor deposition (CVD) and high pressure, high-temperature  (HPHT) processes have already been used since the 1940s.

In order to achieve the coloration of a pink diamond, a multi-step process is typically used. The first step of the process is to create a rough diamond via CVD or HPHT. At this stage, the rough diamond is usually light yellow in color.

The diamond is then subjected to neutron bombardment (irradiation) to introduce the pink hue into the diamond. Thereafter, an annealing process will heat up the diamond to even out the pink hue homogenously.

The resultant manmade pink diamonds would usually possess a color saturation from Fancy Faint Pink to Fancy Vivid Pink. On this note, I want to point out that a lab grown diamond has identical physical and chemical properties as a naturally mined diamond. The main differences lie in their value and people’s perception of authenticity.

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With that, I hope you found this article useful and gained a better understanding of how pink diamonds are formed and made. Given the huge price differences between a natural and manmade diamond, which would you buy and why?

Leave a comment below to let me know. I would love to hear your thoughts!

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