Diamond Formation
When you put on a diamond ring or admire the sparkle of a diamond pendant, it’s easy to forget that every stone carries a story that began billions of years ago.
Before being set forever on a piece of jewelry, a diamond undergoes a long journey.
Born deep within the Earth, diamonds are formed through a geological process involving immense pressure, extreme heat, and an abundance of time.
In this article, we’ll explore how natural diamonds are formed—and why their origins make them so special.
The Origins: Carbon Under Pressure
Diamonds are made out of carbon, one of the most common elements on Earth. While carbon exists in everything from pencil graphite to organic life, diamonds form only when the right conditions come together deep beneath the earth’s crust.
Diamonds originate 90 to 125 miles underground in the Earth’s mantle, where temperatures exceed 2,000°F (1,100°C) and pressures reach 725,000 pounds per square inch (5 GPa).
It’s under these conditions where carbon atoms bond in a tightly organized crystal lattice structure, which gives diamonds their extraordinary hardness and brilliance.
Forming a natural diamond is an extremely slow geological process. It takes anywhere between 1 and 3.3 billion years to form a diamond. Their age is part of what gives them a sense of permanence that lab-grown alternatives simply can’t replicate.
The Role of Kimberlite and Lamproite Pipes
After forming deep underground, diamonds remain locked in the mantle, until a rare geological event sets them on a path to the surface. Deep-source volcanic eruptions create vertical “pipes” known as kimberlite pipes, and in some regions, lamproite pipes. These eruptions act like elevators, thrusting diamond-laden rock upward in a matter of hours.
Because the magma rises so rapidly, diamonds remain intact, embedded in the cooled volcanic rock. These pipes are incredibly rare and exist only in specific geological settings.
Most of the world’s gem-quality diamonds were brought to the surface in ancient eruptions over 100 million years ago.
Once exposed, diamonds may be further concentrated in riverbeds and alluvial deposits over time, as erosion gradually wears away the surrounding rock.
Where the World’s Largest Diamond Mines Are Found
Today’s diamond industry relies on a handful of key sites. It’s here where ancient volcanic pipes have been transformed into major mining operations. Some of the more popular diamond sites include:
- Jwaneng and Orapa Mines (Botswana): These mines are among the most productive in the world. Year over year, they consistently yield high-quality diamonds in large quantities.
- Argyle Mine (Australia): Though it closed in 2020, Argyle was known globally for its distinctive pink and champagne-colored diamonds.
- Venetia Mine (South Africa): South Africa’s largest diamond producer, delivering consistent volumes of top-tier gems.
- Diavik and Ekati Mines (Canada): Located in northern Canada, these mines are known for their advanced technology and ethical mining practices. Despite harsh Arctic conditions, they produce some of the cleanest and most precisely cut diamonds on the market today.
These sites bridge the gap between ancient geological processes and modern jewelry. They are living reminders of the natural forces that make each diamond so exceptional.
Processing: Making the Masterpiece
Once a diamond is mined, it goes through processing to become the finished gemstone you see in fine jewelry. This whole procedure is a mix of technology, skill, and experience.
Processing first starts off with sorting. Not every rough diamond is suitable for jewelry, so each stone is looked at and analyzed for its size, shape, and clarity. The goal here is to figure out what kind of finished diamond it could become. Only around 20% of raw diamonds actually make the grade to go onto become gems of fine jewelry; the other 80% that don’t make the cut are set for industrial purposes.
Next comes cutting. With a gem candidate in hand, the cutting process begins with cleaving or sawing the stone, then shaping it with multiple facets—those tiny flat surfaces that help a diamond reflect and refract light. The placement of each facet is carefully planned to bring out the stone’s natural sparkle, fire, and overall brightness.
Cutting a diamond requires a high level of precision. Even with modern tech, it still relies heavily on the cutter’s skill. Every angle matters here, since the wrong cut can greatly diminish a diamond’s looks and lower its value. Polishing follows, smoothing out each facet and giving the stone its final shine.
Once the cutting and polishing are complete, the diamond is graded. It’s evaluated using the 4Cs—cut, color, clarity, and carat weight—to determine its overall quality. With its grading in hand, a price can be assigned to it accordingly.
With the diamond now cut and graded, it’s ready to be set into a piece of jewelry. Whether it becomes part of an engagement ring, pendant, or custom piece, this process showcases the ingenuity of man – to take a natural wonder formed within the earth over billions of years, and bring about its true beauty to set it on something beautiful and sentimental.
Conclusion
Understanding how natural diamonds are formed adds a certain level of appreciation and wonder for these stones. From being formed over billions of years to being set on your most precious piece, the journey of a natural diamond is a marriage between time, natural wonder, and modern craftsmanship and technology.
Whether you’re choosing a diamond for an engagement ring, a gift, or a custom design, understanding that story brings a deeper connection to the piece you wear.
If you’re in the market for a custom, natural diamond jewelry piece, we invite you to our showroom in the West Loop for a complimentary consultation.
As specialists in custom design, we’ve created one-of-a-kind diamond keepsakes for clientele all over Chicago and beyond.
Stop in to experience our work firsthand and see why Takohl is proud to be one of the city’s most trusted custom jewelers.