Over the last decade, black diamond rings (sometimes marketed as chocolate diamond rings) have been in high demand. It’s almost as if a brand-new gemstone had been discovered without warning, and every woman in the Western world immediately had to have at least one piece of black diamond jewelry.
In reality, the rising popularity of black diamond engagement rings stemmed largely from the 2010 movie “Sex and the City 2”, in which Mr. Big presented Carrie with a five-carat stone “because she’s not like anyone else”. Since then, black diamond rings, earrings, necklaces and other pieces have been seen regularly on the red carpet and at Red Robin alike, with massive ad campaigns contributing to soaring sales of this very unique jewelry.
What is most surprising about the black diamond is that it has been around for centuries, but the jewelry industry considered it unsuitable for use in decorative pieces until quite recently. The industry is certainly making up for lost time, though, pushing the stone heavily and reaping the benefits of its huge popularity.
Before you decide that you just “have” to own a black diamond ring, it would make sense to learn more about the stone and how it’s used – and the difference between natural black diamonds and treated stones. Read on.
What are Black Diamonds, and Why Are They Black?
There are actually several theories on the origin of natural black diamonds, also known as carbonados. The most commonly espoused belief is that they were formed in the same way as all other diamonds: as a crystalline form of carbon created by pressure and heat deep in the earth’s mantle over a long period of time, before being carried to the surface by volcanic eruptions. The distinctive black color is a byproduct of graphite inclusions and clusters of amorphous carbon in the stone, both of which were believed to be present deep in the earth during formation.
Skeptics point to the fact that unlike most types of diamonds, carbonados have only been discovered in central Africa and central South America, far from mines where most of the world’s diamonds are found. They say that would be extremely unlikely, if black diamonds were truly created in the same way as all other varieties of the stone. Some scientists believe there’s a very different story to the carbonado’s origin, with several of their theories centering around meteors. One hypothesis claims that black diamonds were formed when meteors collided with the earth causing what’s called “shock metamorphism”. However, that type of event normally creates diamonds with a different type of crystal structure than is found in carbonados. Another theory focuses on the discovery of hydrogen and nitrogen traces inside black diamonds, leading some scientists to believe the stones were formed in outer space when a supernova exploded, with the diamonds later falling to earth in the form of meteors.
No matter how they were formed, natural black diamonds are opaque due to their polycrystalline structure which absorbs light instead of reflecting it. That means that these gemstones, while beautiful, don’t have the telltale sparkle and fire of clear diamonds. And unlike most colored diamonds, they are only described by one color intensity, fancy black, although most actually look more grey or dark grey than completely black.
Natural black diamonds have the same general mineral characteristics as more common colors of the stone, with extreme hardness (10 on the Mohs scale) and strong thermal conductivity among them. They also have the same density and specific gravity as colorless diamonds. Carbonados are more porous than other diamonds, though, and show strong luminescence believed to be caused by the trace nitrogen inside.
Only about three metric tons of black diamonds have been discovered worldwide, and as previously mentioned, there are only two known sources: small deposits in Brazil and the Central African Republic. Natural black diamonds are quite rare for that reason (although not quite as rare as pink or yellow diamonds), and their price reflects that fact – although they’re surprisingly still less expensive than high-quality colorless stones. We’ll have more on this later, when we discuss buying black diamond engagement rings and black diamond wedding rings.
We’ve spent a lot of time focusing on natural carbonados, but it’s important to stress that most of the black diamonds sold at retail aren’t naturally black at all. “Enhanced” black diamonds are what you’ll commonly see available, and they’re really lower-quality colorless stones which have been treated with radiation or heat to change their color; while they may appear black at first glance, they’re usually more of a very dark green. These treated stones are still real diamonds and usually look shinier than naturally black gems, but will carry a much lower value and therefore sell for a much more affordable price.
We also should mention that some black diamonds sold as “enhanced” are nothing more than poor-quality colorless stones which are simply coated or dyed black. These should generally be avoided completely as the coating can easily come off. You can also find lab-grown black diamonds for sale, which look gorgeous – but aren’t real gemstones at all. There’s nothing wrong with finding a bargain on a beautiful black diamond ring if you don’t mind an enhanced, coated or lab-grown stone; just be sure you know what you’re buying.
The History of Black Diamonds
The creation process for black diamonds spanned billions of years. But black diamonds are “younger” than their colorless cousins by about a billion years or so, and there’s no historical record of their presence in ancient cultures, so we don’t know a lot about their long history. All we have to go on are a few myths which have developed around them. For example, many Indian cultures believed black diamonds to be cursed because they were thought to resemble the black eyes of spiders and snakes, and Italians once believed that a troubled couple could save their marriage by touching a black diamond and “passing their troubles” into the stone.
It wasn’t until the 19th century that the existence of natural black diamonds was actually documented, when King Louis XVIII of France purchased an outstanding carbonado for 24-thousand francs. The first documented use of black diamonds for jewelry dates to 1839, when the collector Henry Philip Hope (of Hope Diamond fame) listed a black brilliant round 1.25 carat diamond in one of his catalogs. Later in the century, a 350 carat black diamond rough was shown at the 1851 World’s Fair, and there are several other recorded instances of carbonados being sold or shown during the 19th century.
There’s a good reason why there are so few records of black diamonds being used for jewelry. Carbonado was widely viewed primarily as a stone only useful for industrial purposes, because numerous inclusions and breaks make it extremely difficult to properly cut the gem into facets and polish it to the degree required for fine diamond jewelry. The rare nature and unusual look of the gemstone, though, has made it a natural for collectors, most of whom don’t exhibit their treasures or even release much information about them. The most famous of the black diamonds known to the public is the 67-carat Black Orlov, sometimes called the “Eye of Brahma”. It’s a brooch with more than 100 white diamonds, whose center stone was made from the black diamond which had once been the “eye” of the god Brahma in an Indian Hindu temple. Other well-known carbonados are the 88-carat Korloff Noir which supposedly brings the owner good fortune, the 202-carat Black Star of Africa which hasn’t been seen since it was displayed in Tokyo in 1971, and the largest carbonado in the world, the 312-carat Spirit of de Grisogno, discovered in the Central African Republic and now hidden somewhere unknown.
Black diamond rings and other jewelry were first widely sold to the public in 1996 when the major Swiss jewelry company de Grisogno (yes, the same one) released its first, gorgeous collection of black diamond pieces. Gem-quality carbonados quickly became accepted in the mainstream jewelry market and have grown in popularity ever since.
Evaluating Black Diamonds
It’s important to know what type of black diamond is featured in a piece of jewelry before being able to evaluate its value. A natural black diamond, needless to say, is far more desirable than an enhanced or lab-created one. So the first step is to find out whether the stone that interests you has been graded by a reputable lab like GIA or AGL; they don’t fully grade artificially-colored or synthetic stones.
However, a lab report on a natural black diamond will contain different information depending on the laboratory doing the research, and you don’t always see the same useful information you’re accustomed to receiving for more common stones. For example, GIA issues two different reports on colored diamonds, one of which is a comprehensive evaluation of color, cut and clarity similar to that of colorless diamonds, while the other is a “colored diamond identification and origin report” which basically determines simply whether the stone is natural or treated. The latter report will suffice for most buyers, since it answers the most important question about black diamonds: are they real?
What you’re most likely to see when shopping for black diamond rings is a rating of “AAA” (the highest rating for optimal cut and polish), AA+, AA, A or I1 (the lowest), with those ratings based primarily on clarity. The problem is that there is no industry or government agency which sets the standards for those ratings; they’re assigned by the jeweler selling the stone. Your best bet, as always, is to know who you’re buying from and only patronize reputable sellers.
Here’s what to look for in a quality black fancy diamond. It will ideally have a simple cut showing the most face-up color possible on a glossy surface, since light reflection from a large number of facets is possible with carbonados. (Black diamonds can be cut into any of the traditional shapes used for colorless diamonds, but expect to pay a premium because of the difficulty that craftsmen have when cutting these stones.) High clarity is nice, but don’t expect to find many stones without numerous inclusions; they’re common in black diamonds. And color should be uniformly distributed, with the best stones closest to a full black.
It’s a lot more difficult to evaluate natural fancy black diamonds than their colorless counterparts. If you’re buying from a trusted seller and have certification that the stone is truly natural, you’re way ahead of the game – the eye test will often be your best guide after that.
Black Diamond Jewelry
Several trends involving black diamonds have emerged in the 21st century. One is the black diamond engagement ring, which as mentioned earlier, surged in sales after the “Sex and the City” character Carrie Bradshaw received a five-carat black diamond ring surrounded by 80 small pavé diamonds from her true love, Mr. Big. The other trend is mixing black and colorless diamonds to create a stunning black-and-white contrast in just about any type of piece imaginable from necklaces, to earrings, to black diamond wedding rings. However, sales of earrings and pendants featuring smaller black diamonds are booming as well. They’re often popular as conversation pieces, since they give women an opportunity to own a non-traditional, stylish diamond jewelry item at a reasonable price.
Without question, though, the sensation of the last five years has been the black diamond engagement ring. There are a nearly infinite number of styles available, from simple solitaires to exquisite combinations of black diamond center and accent stones with halos of pavé diamonds. Two common attributes do stand out when shopping for black diamond engagement rings: the majority feature round or other simple cut stones, and most have white precious metal bands. As you would probably expect, black or white-and-black diamond wedding rings and bridal sets are also big sellers.
One other very popular piece of carbonado jewelry is a man’s black diamond ring, because the color of the stone is viewed by many men as the perfect blend of a precious stone and a masculine look. Men are also more likely to wear a wedding ring matching their bride’s if it features a black stone.
Now, we finally reach the money question: how much do black diamonds cost? As with any diamond, the quality and size of a stone have a major impact on its price. But you can expect to pay anywhere from $2000 to $5000 for a high-quality one-carat natural fancy black diamond. Enhanced black diamonds (which are really lower-quality colorless diamonds which have been treated with heat or radiation), on the other hand, can be found for as little as $300 per carat – not a bad number if you’re searching for the look of a black diamond without the price tag. One last note: it’s not a good idea to buy natural black diamonds with the hope that they’ll appreciate in value. A black diamond is a gorgeous, statement gemstone, but it’s not a good investment.