JEWELRY EDUCATION
Diamond Formation
We love diamonds for their beauty but most people don’t realize they have a story that goes back billions of years. Yes, billions.
These precious gems, created under extreme conditions deep within the Earth, undergo an epic journey before they find their way into jewelry boxes, engagement rings, and heirloom pieces. In this article, we’ll explore the process of diamond formation – looking at how they are formed, how they rise to the surface to be mined, and how they are ultimately transformed into the sparkling gems that adorn our most cherished pieces.
Deep Earth: The Birth of a Diamond
Imagine, if you will, a place so deep within the Earth’s mantle—somewhere between 90 and 150 miles down—that it seems impossible to reach.
It’s here in a region with intense heat and colossal pressure where carbon atoms undergo a metamorphosis. The temperatures soar above 2,000 degrees Fahrenheit, and the pressure is nothing short of unimaginable—725,000 pounds per square inch or more.
Under these extreme conditions, carbon atoms bond together into a crystal lattice that we know as diamond, the hardest natural material on Earth.
It’s not just heat and pressure that shape these stones, though. The formation of diamonds requires precision in environmental factors, creating a perfect storm of chemistry and physics.
In fact, even slight variations in conditions would prevent the formation of diamonds, leaving behind nothing but common graphite. Both graphite and diamonds are made up of carbon, but the way the carbon atoms bond together makes the difference. Billions of years old, each diamond is a relic of Earth’s geological history, waiting to be unearthed.
Kimberlite Pipes: Journey to the Surface
You might be wondering: if diamonds are born so deep beneath the surface, how do they ever make it close enough for us to find them?
This is where kimberlite pipes come in—these are ancient conduits – or “pipes” – of volcanic material that ferried diamonds from the depths of the Earth to more accessible layers of the crust. While there are other ways diamonds can make their ways to the upper surfaces of earth’s layers, kimberlite pipes are responsible as the main source for mined diamonds.
Here’s how it works. Millions of years ago, eruptions that were unbelievably powerful—far more so than modern volcanic activity—created a path for diamonds to hitch a ride to the surface. These eruptions happened with such rapid force that they didn’t just push magma upward; they carried diamonds along with them, embedded within kimberlite, a volcanic rock named after the South African town of Kimberley, where diamonds were first discovered.
This is critical: the speed of the volcanic eruptions ensured that the diamonds remained intact. Had the journey been slower or the heat greater, the carbon would have transformed into graphite. Instead, the diamonds survived, arriving near the surface, where they would rest until discovered by humans.
Today, kimberlite pipes are some of the most prized sources of diamonds, found in regions like Africa, Canada, and Russia.
Humanity’s Hands: The Transformation of a Diamond
Once diamonds have been brought near enough to the surface through volcanic activity, the next chapter of their story begins—the human chapter.
Extracting, cutting, and polishing diamonds requires skill, precision, and a little bit of artistry.
Mining: Unearthing the Treasure
Mining is where the first human intervention takes place. Diamonds may have been carried to the surface by natural processes, but finding them and pulling them out of the Earth is no small feat. Open-pit mining and underground mining are the two primary methods used to extract diamonds from the Earth.
In the case of open-pit mining, large portions of the Earth’s surface are stripped away to reveal the kimberlite pipes below. This method is preferred when the diamonds are relatively close to the surface. On the other hand, when diamonds lie deeper within the Earth’s crust, underground mining becomes the method of choice.
Miners tunnel deep into the Earth, following the path of kimberlite pipes, hoping to find accessible diamonds to be mined. Once the raw material containing diamond is found and thereafter excavated, it must be processed.
First, it’s crushed, and then washed with water. Since diamonds are heavier than most of the surrounding material, this washing process helps to separate the diamonds from the rubble. Technologies like x-ray sorting are then employed to detect the diamonds, which are sometimes tiny and hidden within the rocks.
Cutting: Releasing the Sparkle
Once rough diamonds are extracted, they’re anything but ready for display. In fact, a rough diamond looks nothing like the dazzling stones you see in store windows. This is where the art of cutting comes into play.
Cutting is arguably one of the most important stages in the diamond’s journey because it determines how much light the stone will reflect, which in turn affects its brilliance and sparkle.
The cutter’s job is to find the most efficient way to shape the stone, taking into account any inclusions—tiny imperfections within the diamond—and the natural shape of the rough diamond.
Precision is everything. For instance, the round brilliant cut, which is the most popular and classic cut for diamonds, contains 58 facets (or 57 if you don’t include the culet). Each facet is carefully placed to maximize how light enters and reflects back out of the diamond. This interplay of light is what gives diamonds their signature brilliance.
However, the round brilliant isn’t the only cut. Some diamonds are shaped into princess cuts, emerald cuts, or oval cuts, depending on the stone’s natural attributes or the desired aesthetic. Every cut has its pros and cons, but the skill of the cutter ultimately determines how well a diamond shines.
Polishing: The Final Touch
Once the diamond has been cut, the final step is polishing. Polishing may seem simple but it’s an integral part of ensuring that each facet is smooth and reflective. It’s done to refine any imperfections on the diamond’s surfaces left over by the cutting process.
Polishing enhances the diamond’s brilliance, fire (the dispersion of colored light), and scintillation (the sparkle that occurs when light moves across the stone). It’s this final phase that transforms a diamond from a rough crystal into a brilliant, sparkling gem that’s ready to be set into a piece of fine jewelry.
Conclusion
A diamond’s appeal doesn’t only lie within its signature shine – it also lies within its journey through time. Each stone you see in the showroom is a precise combination of natural wonder and human ingenuity.
So the next time you admire the sparkle of a diamond, remember that you’re not just looking at a gemstone—you’re holding a fragment of the Earth’s ancient past that’s been processed by humans to make something that’s timeless.
If you’re curious about finding the perfect diamond or want expert advice on selecting a stone that will shine for a lifetime, our team at Kosmima is here to help. With decades of experience servicing the Greater Boston Area, we’re here to guide you in finding a diamond that will be cherished for years to come.
