At first glance, diamonds look like little more than small, faceted pieces of glass — they’re transparent, they sparkle, and sure, they sit really nicely on jewelry. But when you take a closer look, the true value of diamonds becomes more apparent. After all, there’s a reason that diamonds are the world’s most popular gemstones.
Want to know a bit more about what makes diamonds so special? Here are 20 interesting diamond facts to get you started.
1. Mined diamonds form very deep underground
It’s no secret that mined diamonds come from underground, but most people aren’t quite aware of how far underground we’re talking about. Diamonds are formed far below the earth’s outer crust, approximately 100 miles down in the upper mantle. To offer a sense of perspective, the deepest hole ever drilled only made it about 7.5 miles (or about 12 kilometers) down. We’d need about 13 such holes to reach prime diamond-making depth.
2. Diamonds are pure carbon
What is a diamond? Well, when it comes to making diamonds, the ingredient list is pretty short. In fact, all you need is carbon. Carbon is an element commonly found on earth, and is unique in that a single carbon atom can form chemical bonds with up to four other atoms. When these atoms bond with four other carbon atoms tetrahedrally, it forms a rigid, three-dimensional crystal of unmatched hardness.
3. Diamonds and graphite are made of the same thing
Graphite — the slick, dusty material that gives modern pencils their mark-making ability — is also made from crystallized carbon. So why is diamond so different from graphite? Well the answer lies in the structure; much like in diamonds, graphite’s carbon atoms are bonded to four other carbon atoms. But unlike the tetrahedral structure found in diamonds, graphite atoms are arranged more two-dimensional — layered, like chicken wire. This allows the layers to separate easily… which is something diamond simply doesn’t do.
4. No one is quite sure how long it takes diamonds to form in the ground
The diamonds that are mined from the ground are generally extremely old — billions of years old, nearly as old as the earth itself. But the processes involved in creating these diamonds are a bit harder to clock. It may take billions of years for a diamond to grow, or it may take as little as a matter of hours. At the same time, the processes may not be consistent; environmental conditions could change, a diamond may stop growing for a few million years, and then the process might resume.
5. It takes a lot of heat and pressure to make diamonds
We may not understand how long a diamond takes to form underground, but we have a good idea of how much heat and pressure is needed. To get the process going, you need about 725,000 pounds (328854.5 kilograms) per square inch of pressure, and temperatures of around 2200°F (1200°C). This allows the carbon atoms to bond together correctly, instead of just ending up as crummy old graphite.
6. Diamonds are brought to the surface by explosive volcanic eruptions
For diamonds to travel from the upper mantle to the outer layers of the earth’s crust, they need to hitch a ride with a volcano. That said, most volcanic vents simply don’t go deep enough. Kimberlite volcanoes, on the other hand, reach far down into the upper mantle. During a kimberlite eruption, diamonds and surrounding material is explosively pushed to the surface by rapidly expanding gases. Kimberlite volcanoes are very rare, and scientists believe that the most recent kimberlite eruption may have occurred as far back as 10 to 20 million years ago.
7. Diamond may not be the hardest substance after all
According to the Mohs Scale (named after mineralogist Friedrich Mohs), diamonds are the hardest substance in existence. In fact, they’re about four-times as hard as the second hardest substance on the scale. Unfortunately, it looks like the Mohs Scale may be somewhat out of date. Both wurtzite boron nitride and lonsdaleite might be harder than diamond, depending on how you measure it. Oh, and it’s speculated that dying stars pack atoms together so tightly that the resulting “nuclear pasta” makes diamond look like tissue paper. But given that a single gram of nuclear pasta would likely weigh about 1,500,000 tons, you probably wouldn’t have much luck wearing it on your finger.
8. Not all diamonds are colorless
Although colorless diamonds are generally considered the most valuable, diamonds can be found in a range of colors, including green, blue, yellow, brown, orange, purple, red, or even black. The color of a diamond is dependent upon the inclusion of trace elements within the diamond, or the introduction of other imperfections or impurities during formation.
9. Diamonds are named for their hardness
The modern English word diamond has origins in the Greek word adamao, which means “I subdue.” This root word shows up in other, similar words, such as adamantine, meaning “unbreakable.”
10. For a long time, diamonds were only found in India
Diamonds have been traded for thousands of years, and as far back as the 1st century AD, were already considered by some to be the most precious stones in the world. But it wasn’t until the 1700s, when India’s diamond supplies started running short, that diamond mines began cropping up in other parts of the world.
11. Most of the world’s mined diamonds come from only a handful of countries
Russia and Botswana are the world’s leading diamond producers, accounting for over half of the world’s annual diamond production. Canada, Angola, and South Africa are responsible for most of the remaining diamonds. Together, these five countries produce approximately 88% of the world’s diamonds.
12. Most mined diamonds are not used in jewelry
Thanks to their extreme durability and hardness, diamonds are useful in a range of industrial applications, including cutting, drilling, polishing, etc. And, because a large portion of rough, mined diamonds are unsuitable for jewelry, approximately 80% of mined diamonds are put to work as industrial diamonds.
13. The Cullinan Diamond is the largest gem-quality rough diamond ever found
Discovered in South Africa in 1905, the Cullinan Diamond originally weighed a whopping 3,106.75 carats. It made its way into the hands of the British Royal Family, and was eventually cut down into nine separate diamonds, with the two largest (Cullinan I and Cullinan II) currently holding places of prominence as part of the Crown Jewels.
14. Traditional diamond mining is dangerous and environmentally damaging
In total, diamond mining results in approximately 1 injury for every 1000 workers annually. At the same time, for every single carat of diamond mined from the ground, around 100 square feet of land are disturbed and nearly 6000 lbs of mineral waste are produced.
15. It is possible to grow real diamonds in controlled conditions
Lab-grown diamonds are chemically and structurally identical to mined diamonds. In fact, in 2018 the Federal Trade Commision amended its Jewelry Guides, eliminating any distinction between lab diamonds and mined diamonds.
16. Lab-grown diamonds were first made in the 1950s
While lab-grown diamonds are only beginning to change the face of the diamond industry, the first man-made diamond was actually created nearly 70 years ago. General Electric funded the process, and the resulting diamonds were generally smaller than 0.1 carats and used in their unpolished form for industrial purposes.
17. There are two processes labs use to grow diamonds
To create diamonds in a lab, diamond producers rely on one of two possible methods: High Pressure-High Temperature (HPHT) or Chemical Vapor Deposition (CVD). HPHT replicates the extreme heat and pressure found within the earth to melt carbon and force it to bond together, crystalizing into a diamond. CVD takes a slightly different approach, heating a carbon-rich gas until it turns into plasma, allowing the carbon to crystalize and grow around a small diamond starter seed. HPHT was developed first, but the CVD process is widely considered the superior approach.
18. Lab-Grown Diamonds cost less and create less waste
While diamond mining can be a hazardous, environmentally unfriendly process, growing diamonds in a lab is ethical and ecologically responsible. And, because lab-grown diamonds eliminate the long supply chains associated with the mined-diamond trade, they can be sold for significantly less; a lab-grown diamond will generally cost 20–30% less than a mined diamond of the same quality.
19. Lab diamonds can be grown very quickly
While we may not be sure how long it takes for diamonds to form underground, we know that growing diamonds in a lab is a relatively fast process. A single carat diamond can be grown in around one month.
20. Lab-grown diamonds are available in all shapes and sizes
No matter what kind of diamond you’re looking for, there’s a lab-grown solution waiting for you. Click here to browse our collection of high quality diamonds.
Just like diamonds on glass, these 20 facts are scratching the surface. Want more information on diamonds? Contact us today; we love talking about diamonds, and we’re always up for a chat.