There are three main diamond varieties: mined, lab-grown, and treated. Each type has its own unique story and appeal, making it crucial to understand your options. Alongside these types, the four Cs — cut, clarity, colour, and carat weight — play a pivotal role in determining a diamond’s quality and value. 

Whether you’re drawn to a mined gem or intrigued by the modern innovation of lab-grown diamonds, knowing these factors will help you find the perfect diamond that fits your style and values.

The most common and well-known diamond type is the earth-mined kind, which lies deep within the Earth’s mantle and is formed under immense pressure and heat. Composed entirely of carbon atoms, these diamonds are prized for their exceptional hardness and brilliance and have been around for millions, if not billions, of years.

They emerge through volcanic eruptions, surfacing through kimberlite pipes, and are then mined and cut to reveal their beauty. Their rarity and the natural processes behind the stones' formation contribute to their enduring allure and value.

But what if there’s a way to produce diamonds that would be kinder for the planet and its people? Introducing lab-grown diamonds (or man-made diamonds), a diamond variety created through modern technology that allows us to replicate the process of mined diamond formation within a lab. To do this, there are two different processes: 

There’s HPHT (High Temperature, High Pressure), where a small apparatus mimics the environment that a mined diamond undergoes beneath the earth’s surface. Temperatures exceeding 1,300 degrees Celsius and 50,000 atmospheric pressure are applied to a carbon source, turning carbon atoms into a rough diamond crystal. 

Another option is CVD (Chemical Vapour Deposition), where a diamond seed is placed into a CVD chamber and combined with high temperatures and hydrocarbon gas to create a plasma globe. When the gases’ molecular bonds begin to break down, the pure carbon attaches itself to the diamond seed, forming atomic bonds and turning the seed into a much larger rough diamond. 

“Sustainably created without displacing land, wildlife or communities.”

The result? A rough diamond that’s chemically the same as an earth-mined diamond but without the ethical and environmental price tag. In fact, after the polishing process, jewellers, gemologists, and scientists can not tell the difference between earth-mined diamonds and lab-grown diamonds, resulting in them being graded the same way.

Every created lab-grown diamond is entirely unique, which is then polished and cut with its own clarity characteristics. And no, there’s chemically or aesthetically no difference between a mined and a lab-grown diamond!

Treated diamonds can be broken down into two main categories. The first way these types of diamonds can also be treated is to enhance their colour (colour modifications). From ruby red to emerald green, this modification produces a vibrantly coloured diamond, using processes to change the atoms such as annealing, irradiation and HPHT. These treatments are permanent and cannot be reversed. What’s more they can be used for both earth-mined diamonds and lab-grown diamonds. 

Did you know? On GIA or IGI reports (which you’ll get when you purchase your diamond), there will be a comment that includes whether a lab-grown or earth-mined diamond has been treated. 

The second process is clarity treatments, including fracture filling and laser drilling. During fracture filling, for example, the diamond cavities are filled with silicone and other compounds to enhance their look. Although this filling is barely noticeable, making them look fairly similar to flawless earth-mined diamonds, they’re dramatically lower in price. 

Although all types of diamonds mentioned above explain the differences well to a buyer, the industry uses different terms. When we classify diamonds, we do so based on their physical and chemical attributes, assessing how they’ve formed and whether they’ve been treated.

Type Ia Diamonds: Gems where nitrogen gathers in clusters, giving off a yellowish tone. This is the most common type of diamond and has many sub-sections based on the nitrogen aggregations. 

Type IIa Diamonds: Rare diamond types that have no measurable nitrogen or boron impurities in comparison to other type I and II diamonds. This makes them more expensive and they will typically have some of the highest colour gradings. Interestingly, the majority of lab-grown diamonds are Type lla. 

Type Ib Diamonds: Also quite rare, the main feature of these diamonds is that individual nitrogen atoms are scattered throughout the gem (and not in clusters). This allows a lot of visible light to be absorbed, colouring the stone in an often powerful yellow, orange, or brown hue.

Type IIb Diamonds: This rare diamond type has no nitrogen atoms. However, they do contain boron, as well as its main carbon content. Boron is what makes fancy blue-coloured diamonds ‘blue’, which is why Type llb are so expensive.

When evaluating different types of diamonds, the Four Cs — cut, clarity, colour, and carat — are vital in determining their quality and value. These essential qualities help you navigate the dazzling world of diamonds, ensuring you find a gem that perfectly fits your style.

While many people think of cut as the diamond’s shape, it actually focuses on how the stone’s facets interact with light. The cut is, therefore, crucial to its overall brilliance, referring to how well the diamond’s proportions, symmetry, and polish are crafted. A well-cut diamond will maximise its brightness, brilliance, and scintillation, having light expertly reflected and refracted through its surface.

Clarity is all about the natural imperfections, or inclusions, within a diamond that defines its unique character. These tiny flaws, like minerals or crystals, can influence how light travels through the stone. The fewer inclusions a diamond has, the clearer and more luminous it will appear. 

While most diamonds have some inclusions (often invisible to the naked eye), they contribute to the stone’s individuality, much like our own unique traits. This is graded on a scale from Flawless (FL) to Included (I1, I2, and I3), with higher grades signifying fewer visible imperfections and greater brilliance. 

Colour is a key factor in determining a diamond’s beauty and value, and it’s often the first thing you notice. The ideal type of diamond is typically colourless, with the highest value attributed to those lacking in any hues. However, diamonds come in a spectrum of colours, ranging from D (colourless) to Z (noticeable colour), each grade impacting the stone’s appearance. From subtle tints to vivid hues like pink, blue, or yellow, they can also be highly sought after.

Note: There is a colourless grading scale as well as a fancy colour grading scale. When talking about fancy colours this will be anything like pinks, blue, yellow, brown, red, purple, orange, or green (see the GIA’s fancy colour scale below).

Lastly, the carat measures a diamond’s weight and is a significant factor in its value. Larger diamonds are rarer and generally more expensive, making carat weight a significant consideration for buyers. However, the carat alone doesn’t determine a diamond’s overall appeal; its true worth also depends on its cut, colour, and clarity. Therefore, use the carat as a size indication rather than its value!

When you look at the different types of diamonds, your personal preference and practical considerations lie at the core of deciding which one’s best for you. Start by reflecting on what matters to you most:

• Do you prioritise mined diamonds?

OR

• Are you drawn to the ethical and sustainable benefits of lab-grown options? 
• Is a lower price point a factor? 

OR

• Are you looking for a unique look with treated diamonds? 

Consider what resonates with your values and lifestyle to find the perfect diamond that’s as meaningful as it’s beautiful.