How to Buy a Black Diamond – A Stunning Gem

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Dream of owning a black diamond? Learn the essentials of how to buy black a diamond in this thorough guide! We cover the 4 c's and more!

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It is imperative that you buy your black diamonds from a reputable dealer that offers high-quality photos and GIA certification. We recommend James Allen for their selection and excellent customer service. 

Black is beautiful; black is the most colorful shade because it mixes all the colors! Learn how to buy a black diamond in this thorough guide.

Black diamonds are a unique and unusual stone; their magical and mystical aura will enchant almost anyone. Most people are familiar with sparkling white and colored diamonds, but black diamonds are a new and upcoming trend. 

Historically, black diamonds were held in low regard and only started to gain popularity towards the end of the 20th century. With a very distinctive and bold appearance, black diamonds are unconventionally beautiful, making them highly desirable to people who want something unique. Nowadays, it is pretty common to find black diamond jewelry such as engagement rings, earrings, and bracelets. In addition, black diamonds are quite popular in high-end jewelry.

how to buy black diamonds

What are Black Diamonds?

Black diamonds have an element of mystery attached to them, as there are a few theories behind their origin. One of them hypothesizes that black diamonds fell on the Earth as meteorites.    

Just as with white diamonds, black diamonds form under intense heat and pressure conditions. However, unlike other color diamonds that receive their color from geological impurities such as nitrogen, hydrogen, and boron, black diamonds get their color from a high amount of graphite inclusions and random clustering. These inclusions block light to the point that the diamond appears black.

Black diamond is also known as carbonado, and it is one of the toughest forms of a natural diamond. All diamonds score 10 on the Mohs scale. However, black is the hardest diamond of them all. 

Types of Black Diamonds

There are two types of black diamonds: natural fancy black diamonds and treated (or enhanced) black diamonds. 

Natural black diamonds get their color from graphite inclusions and are only found in Central Africa and Brazil

Treated black diamonds are colorless diamonds turned black by heat or radiation treatments. Colorless diamonds with lots of inclusions get used for this process. The undesirable inclusions are hidden once the surface of the diamond turns black and opaque.

Salt and pepper diamonds are a variation of black diamonds. These diamonds also have lots of inclusions but are translucent instead of opaque.

how to buy a black diamond

The 4 C's of Black Diamonds

When judging the quality of a black diamond, be sure to check the certification to see if it is natural or heat-treated; when it comes to the 4 C's, color and clarity matter the least. Black diamonds are heavily included, and there is only one color rating - fancy black. Cut is the most important of the 4 C's. 


Black diamonds are opaque with high luster and a metallic appearance. Their black hue comes in only one color intensity, i.e., fancy. Apart from black diamonds, only fancy white and fancy red have a single intensity grade, whereas other colors can be found in up to nine grades - ranging from faint to deep. 

As they are not transparent, they do not exhibit sparkle and fire like other white or fancy colored diamonds, but still are spectacularly impressive and beautiful.  


The high number of inclusions in a black diamond absorbs light and hence does not refract light in the same manner as other diamonds. Due to this, clarity is not an essential factor in grading black diamonds.


Cut is the main factor to consider when choosing a black diamond. Because black diamonds contain numerous graphite inclusions, they are difficult to cut without fracturing, which means high-quality cuts can be expensive.

Instead of being cut to maximize brilliance, as with white diamonds, black diamonds are cut to show their unique features and maximize the absorption of light. You will typically find black diamonds in round, cushion, and pear shapes but will have to look harder (or pay more) for other shapes.

To maximize the sparkle of a black diamond, look for a rose-cut or one with a small table and large crown facets. 

To buy a high quality natural black diamond, it is crucial to ensure that the stone has a smooth, glossy, and shiny surface with no visible lines or blemishes.


Natural black diamonds are denser than other white or fancy colored diamonds, and therefore, a black diamond will be smaller in size than the same carat white or colored diamond. E.g., a one-carat black diamond will have a smaller size than a one-carat white diamond.

When choosing a black diamond, focus on the cut and shape rather than the carats. 

Watch: What is a Black Diamond?

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Rarity and Pricing of Black Diamonds

Natural black diamonds are considered to be fancy colored diamonds. Most natural fancy colored diamonds are extremely valuable due to their rarity, and their color intensity highly influences their price.

Though black diamonds are not one of those rare fancy colored diamonds (such as red, pink, or green), they are highly valued for their bold glamour and distinctive beauty. Due to their bold appearance, they are greatly favored in men's jewelry

Black diamonds are comparatively more affordable than other white or fancy color diamonds, which is majorly due to lower demand. The size of a black diamond is also a considerable factor affecting its price. The cost of a natural black diamond may range from $3,000 to $5,000 per carat. Also, it is essential to differentiate between natural black diamonds and treated black diamonds as the former are much rarer and expensive than the latter ones.  

Grading of Black Diamonds

As black diamonds are opaque and full of inclusions, they cannot be graded by certified laboratories on general parameters like other white or fancy colored diamonds.

Simply speaking, black diamonds are considered to be perfect when :

  • They are entirely dark.
  • They have a uniform hue.
  • Their facets are well-cut.
  • There are no visible lines or spots.
  • They have a glossy and shiny surface.

Natural black diamonds are graded on the above qualities. However, the critical point to note is that color-enhanced or lab-treated diamonds are not graded or certified.

  • Natural AAAA: AAAA graded black diamonds are the perfect natural black diamonds. They are extremely rare and comprise less than 1% of natural black diamonds. Therefore, they are exorbitantly priced and coveted by collectors, connoisseurs, and investors.
  • Natural AAA: AAA graded black diamonds have a uniform hue with a glossy surface. These black diamonds are quite rare, with only 1% falling under this bracket.
  • Natural AA: AA graded black diamonds have a slightly lower color intensity and contain some minute surface flaws. However, these flaws are not visible through naked eyes, and hence they can be the best choice when considering fine jewelry. 10% of natural black diamonds fall under this bracket.
  • Natural A: 20% of natural black diamonds are under this category. Though they are not as fine quality as higher grade ones, they are still deemed a good choice for jewelry.
  • Natural B: 50% of natural black diamonds fall in this category. They are not an excellent choice for jewelry.      

Metal Choices for Black Diamonds

Black is a highly powerful color, and wearing a black diamond speaks of a powerful persona and authority. The black color also symbolizes love and romance

Black diamonds can look exceptional when paired with complementing metals, and therefore it is imperative to choose the base metal carefully. Metals such as white gold and platinum make the best pair for black diamond jewelry, including engagement rings.

Black diamonds can also make a stunning pair with yellow gold and rose gold.   

Watch: What are Black Diamonds?

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Black Diamonds for Engagement Rings

Black diamonds are gorgeous and immensely enchanting due to their unique appearance. If you are looking for something less traditional, a little edgier, and striking, then a black diamond can make a perfect engagement ring.

Although these diamonds are hard and won't scratch, their brittleness does put them at risk of being damaged. Smaller black diamonds are less likely to fracture. You can incorporate small diamonds in a wedding band or pair them with a different center stone. Colorless diamonds, emeralds, or rubies look stunning, surrounded by black diamonds. 

  • A round-cut black diamond engagement ring is perfect for someone looking for a timeless look.
  • For a modern look, pair black diamonds with colorless diamonds or rubies in a platinum setting. 
  • A princess cut emphasizes the unique beauty of this dark gemstone. A princess cut reduces the visibility of flaws and inclusions, creating a stunning stone with a subtle sparkle.

Black Diamond Engagement Ring Settings

A proper pairing and setting can enhance the look of an engagement ring so you can admire and cherish it lifelong.

  • Side stone setting: Black diamond can be highlighted by adding two colorless diamonds of any cut on either side.
  • Halo setting: Surrounding black diamonds with small colorless diamonds can create a magnificent effect.
  • Solitaire setting: A black diamond can be made the focus of attention with a solitaire setting. The only thing to note is to pair a black diamond with white gold or platinum for contrast and an eye-catching effect. 

Natural vs. Color Enhanced Black Diamonds

Most of the black diamonds available in the market today are color enhanced, or laboratory treated because of the rarity of naturally occurring black diamonds.

  • Color-enhanced black diamonds undergo rigorous chemical processes to appear black, unlike true black diamonds that are naturally black. 
  • Natural black diamonds have a porous structure that allows more light absorption, making them more opaque. On the other hand, treated diamonds are less opaque and less valuable than their natural counterparts.
  • Color-enhanced black diamonds are more affordable than natural black diamonds. They can prove to be a great choice if budget is an issue, but your heart is set on a black diamond.

Are Black Diamonds Worth the Investment?

An investment diamond will rise in value over the years as its supply deteriorates and demand for them continues to increase. However, black diamonds are not in very high demand despite their rarity. Therefore, one would only be considered an investment item if it was considerably large or had a distinctive feature that would make it very desirable to investors in the market.

Where to Shop for Natural Black Diamonds

Buying a diamond requires a great deal of knowledge and research, and therefore, buying a diamond is not an easy affair.

It is highly recommended to buy black diamonds from reputed sellers. One of the most trusted and reputed diamond sellers is James Allen.

  • They are the leader in online diamond sales.
  • They have 18+ years of experience. With the prime focus on customer satisfaction, they provide excellent pricing for their diamonds.
  • They have the highest tech diamond imagery in the industry, which makes it easy to accurately search and review diamonds.
  • They offer a wide range of setting options for black diamond engagement rings.

Click here to visit James Allen and add a powerful and glorious black diamond to your collection!

We hope this guide on how to buy a black diamond has helped you. If you have any questions, please don't hesitate to leave them in the comments, we always answer.

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3 thoughts on “How to Buy a Black Diamond – A Stunning Gem”

  1. This is the first time I’ve studied this.
    My strong wife would have liked a black diamond ring even the cheapest.
    Now I realize it would have been an amazing memory.
    I have few valuables left of it, but it would have been priceless.
    How nice to know these things about black diamonds 30 years ago!

  2. Great article. 

    I have a question, What should I look for when buying a black diamond?    

    I used to see so many type and I don’t even know how to clearify the original.                                                                                                                                               

    • Hi Emmanuel, thanks for stopping in. When purchasing a black diamond, along with keeping the information in mind provided in this article, it is best to look for a black diamond with a mirror like surface free of any nicks, chips, scratches, or cavities. If you choose a natural black diamond, insist on a GIA report. 


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