How are Natural Diamonds Formed?

Diamonds are admired for their sparkle, but the story of their formation is just as inspiring.

Every natural diamond’s journey begins deep in the earth, billions of years ago. It’s here where conditions of extreme pressure and heat react with carbon to create the stones that the world loves today.

At Sunshine, we understand that oftentimes the sentiments of a piece of jewelry are just as important as its beauty. Learning about the formation process helps give a deeper appreciation for diamond pieces and why they’re rare and meaningful treasures.

In this article, we’ll walk through the story of natural diamonds:  We’ll discuss how they’re formed, how they reach the surface, and how they are transformed from rough crystals into polished gems that we have all come to know and love. 

Diamond Origins

Diamonds are made entirely of carbon. You may recall other things that are made out of the same element: coal, graphite, and even life itself.

What makes the formation of diamonds unique is how carbon atoms are arranged. Deep within the earth, where carbon is naturally present, there are conditions of extremity. It’s here, 90-120 miles beneath the earth’s surface, where temperatures reach over 2,000°F and pressures get to 725,000 pounds per square inch (around 50,000x greater than the pressure of air at the surface).

When exposed to this environment for extended periods of time, carbon atoms bond together in a formation known as a three-dimensional lattice. It’s this structure that’s responsible for making diamonds, diamonds, with their unmatched hardness. To contrast this, carbon that forms graphite, which is soft, is arranged into layered sheets rather than a three-dimensional lattice. 

It’s important to underscore that natural diamond formation happens over extraordinary spans of time. It can take billions of years for carbon to transform into the rough crystals that eventually become diamonds.

The stones we see today began forming long before we humans even walked the earth, making every natural diamond a rare piece of ancient history.

Natural vs. Lab-Grown Diamonds

Lab-grown diamonds are physically, chemically, and visually the same as their mined counterparts; the only difference lies in where they come from.

Lab stones are created in a matter of months using modern technology, and because of this, they don’t carry the same sense of rarity. 

Natural diamonds are finite. They were formed by geological processes that took place billions of years ago and cannot be repeated. It’s this important factor that makes them so valued. Furthermore, this scarcity helps natural stones hold their value over time. 

Kimberlite and Lamproite Pipes

After being formed within the earth’s crust, diamonds then need a way to get to the earth’s surface to be mined. 

This process happens due to nature, as well. After diamonds were naturally formed in the Earth’s crust, powerful volcanic eruptions carried them upward towards the surface  in molten magma. When the magma cooled and solidified, it created vertical channels of rock that contained the raw diamonds it carried upwards. 

These channels are known as kimberlite pipes, and are where diamonds are traditionally mined from.

Diamonds are mined in a few different places around the world, but there are only a few countries that have mines that produce them in large quantities:

• Botswana and South Africa – Famous for producing some of the highest-quality diamonds and some of the world’s largest stones.
  

• Canada – Known for mines in the Northwest Territories, with a strong focus on transparency and ethical sourcing.
  

• Australia – Once home to the Argyle mine, which produced rare pink and champagne-colored diamonds.
  

• Russia – One of the leading producers by volume, with vast reserves in Siberia.
  

• From Rough Crystal to Finished Gem

Once diamonds are extracted from mines, they are still in their raw form, far from being fit for a piece of jewellery. It’s estimated that only about 20% of raw diamonds are actually fit for becoming sparkling gemstones, the rest being left for industrial uses.

For the diamonds that are destined to become gems, the transformation requires both advanced technology and the steady hand of a skilled craftsman. 

Each stone is carefully examined to determine the best way to cut it so that its natural beauty is uncovered. 

The cutting process can take weeks or even months, depending on the size and quality of the stone. Afterward, the diamond is polished to bring out its fire and sparkle, and then graded on the 4Cs—cut, clarity, color, and carat weight—before finally being set into a piece of jewellery.

Why the Diamond Story Matters

Diamonds are more than gemstones; they’re artifacts that celebrate nature’s power and beauty. They carry a history that stretches back billions of years, formed under extreme conditions deep within the Earth. Their rarity lies not only in their beauty but also in the fact that the geological processes that created them no longer occur today. Unlike lab-grown diamonds, which can be replicated in controlled environments, natural diamonds are finite.

This is why natural diamonds are often chosen for life’s most meaningful moments - something that we celebrate at SUNSHINE. 

If you’re considering a diamond, we welcome you to our Philadelphia or Media showrooms.

 Whether you’re exploring engagement rings, custom designs, or just want to learn more about diamond quality, our team is here to guide you. 

With a GIA gemologist on staff, we’ll help you choose a stone that feels right for you—one with both natural wonder and lasting meaning.