All About Black Diamonds

When you think of diamonds, you probably imagine a colorless, brilliant cut stone. In recent years, however, many celebrities have rocked fancy colored diamonds, including Lil Uzi's pink forehead diamond and the Tiffany yellow diamond Lady Gaga wore at the Oscars. Today, we're gonna look at one color in particular, black diamonds. How do they form? Are they really from outer space? Are they valuable? And why are we so obsessed with them? Let's find out. As with a diamond of any color, their black diamonds are billions of years old. There are some claims that black diamonds are younger, not having reached their full diamond potential. Nothing could be further from the truth. To know why black diamonds are black, we must first explore how diamonds form. Imagine being deep inside the Earth's mantle, not the core, not the crust, but the mantle, which is over 80% of Earth's volume and made up of crystalline iron-rich rock. The formation of natural diamonds requires very high temperatures and pressures. These conditions occur in limited zones of Earth's mantle, about 90 miles or more below the surface, where temperatures are at least 2,000 degrees Fahrenheit. During deep source volcanic eruptions, diamond-bearing rocks called kimberlites are swept up by the molten magma on its journey to the surface. Diamonds can be mined from these kimberlites or found in river and beach gravel deposits where they accumulate after the kimberlite around them erodes away. In fact, this is where black diamonds are usually found, but there are some theories that suggest some diamonds could have come from space. There are two other ways in which diamonds are thought to form that are a little more out of this world. One is through asteroid impact. Throughout its life, the Earth has been hit by many large asteroids. When these asteroids strike Earth, they produce extreme temperatures and pressures great enough to manufacture diamonds. This theory is supported by the discovery of tiny diamonds around several known asteroid impact sites. Who knew? Next, diamonds are from outer space. NASA researchers have detected large numbers of nanodiamonds in some meteors. A nanometer, by the way, is a billionth of a meter in diameter. These are seriously small diamonds. Only about 3% of the carbon in these meteorites comes in the form of nanodiamonds. They're not even big enough to be used for industrial purposes, so don't go digging up your backyard when you see a falling star. The likelihood of you finding one is little to none. Well, maybe not little to none. Recently, a billion-year-old black diamond, thought to be the largest cut in the world, was bought at auction using cryptocurrency for $4.3 million. What's unique is that this 555.55 carat black diamond, originally called the Enigma, is a carbonado diamond, which is found in deposits close to or on the Earth's surface. Carbonados are only found in Brazil and the Central African Republic, which were connected for more than a billion years as the supercontinent called Rodinia. Sotheby's Auction House said, this adds to the theory that carbonados come from space, as it was while they formed part of this supercontinent that the area was believed to have been struck by meteorites. You may be asking, why are black diamonds black? It's a great question. The answer was only recently discovered. Naturally, black diamonds are so because of numerous minute mineral inclusions. These can be graphite, pyrite, or hematite, all of which extend throughout the stone. These diamonds may also have cleavages and fractures that were stained or became black due to graphitization while forming. In fact, the actual body color of a natural black diamond could range from near colorless to brown to olive green. It's the concentration of these internal features that makes them appear black. Most fancy colored diamonds are colored so because of elemental impurities introduced while they're forming. In the case of yellow and blue, it's nitrogen and boron respectively. The cause of pink and red is a little more complicated. It's called plastic deformation. Plastic deformation occurs at increased temperatures and pressures during the post-growth stage of a diamond's crystal lattice, where there's a slipping of blocks of crystals over one another along different crystallographic planes. Think of it like shuffling a stack of playing cards. At extreme temperatures, the diamond atoms become mobile and during the process of deformation, they dislocate and slip. These irregularities change the way the electrons absorb light. Therefore, they're responsible for the creation of pinks, reds, and brown colored diamonds. You may be thinking, if pink, yellow, red, and even some brown diamonds are considered fancy colored, then black diamonds are too, right? Well, sort of. Black diamonds are only called fancy black because there's no exact grading system for them, but they gotta be grouped somewhere. The four Cs of color, clarity, cut, and carat weight is the standard by which colorless to near colorless diamonds are graded. Black diamonds fall outside this grading color range, so their color is evaluated based on GIA's color grading system for colored diamonds. Furthermore, because black diamonds are opaque and in most cases, heavily included, GIA does not grade their clarity. Also, there's no variation in the tone and saturation of a black diamond. Unlike their pink, yellow, and blue counterparts. So, only the single grade term fancy black is used. Lastly, GIA does not issue grading reports for these diamonds. Instead, they issue a colored diamond identification and origin report. This simply states that the diamonds are described as fancy black, and their color is noted as either natural or treated. Unlike a colorless or fancy colored diamond, when light enters a black one, a lot of it is absorbed. Black diamonds also have a very lustrous metallic appearance due to the metallic inclusions throughout the stone. And if you thought white diamonds were hard to cut, black diamonds are even more so. The graphite inclusions tend to make them even more brittle, and it can take up to a year for a diamond cutter to complete a faceted black diamond. This is probably why you've only heard of a handful of famous black diamonds. They're just too hard to cut. So, why are we obsessed with black diamonds today? Let's discuss. Our best guess is it's because black diamonds are unique and dramatic, which draws collectors to them. A popular theory in Italy is that touching a black diamond can save an ailing relationship because the diamond absorbs the problems. When it comes down to it, beauty truly is in the eye of the beholder. And this beholder just thinks they're cool, man. Tell us, what do you think the real reason black diamonds are becoming so popular is? And since GIA doesn't grade them like other diamonds, would you be willing to pay a higher price for one? Let us know down in the comments, and don't forget to like, subscribe, and ring the bell so you don't miss out on future diamond episodes. Thanks for watching.