In the previous articles, we spent some time taking a detailed look at the origins, history, and the process of extraction of diamonds. Still, diamonds are some of the most elusive things you can find on Earth – and taking a deeper dive into their lore is never a bad thing.
But, even if you’re aware of these fascinating facts, getting to know the world of diamonds can still be very intimidating. If for nothing else, then for the very fact that this priceless gemstone features so many different categories and types. It’s incredibly easy to get lost.
As a matter of fact, most of the regular folk don’t even know where to start because how would you even divide diamonds into categories – by origin, size, color, or cut? All of the above?
The answer is, we have yet to find some one-size-fits-all solution for this conundrum. So, we’ll go for the second-best resolution: Try to isolate as many different diamond groups and organize them in some sensible manner.
So, fasten your seatbelts; these are all different types of diamonds you can find on Earth.
Types Of Diamonds For Casual Shoppers
This is probably the broadest and the most basic way to divide all the diamonds currently in use around the globe. So, let us start with these basic steps before we proceed to a more detailed outlook.
Here are the four main groups of diamonds:
1. Natural Diamonds
A natural gem is probably what most of us like to imagine when the word “diamond” pops up in the conversation.
Essentially, natural diamonds are transparent, colorless precious stones that formed millions of years ago, traveled near the Earth’s surface through Kimberlite pipes, and were finally extracted from the depths through mining.
Until the discovery of other naturally formed diamonds and artificial production of this material, this type of diamond was the only type humanity ever knew. So, they have pretty much set the pattern for the rest of the bunch.
Due to their scarcity, limited deposits, and irreplaceable physical properties, they are the most valuable diamonds, mainly used as precious stones and very rarely for industrial purposes.
2. Lab-Grown Diamonds
Lab-grown diamonds were first produced in December 1954 by a group of scientists from General Electric. They essentially emulated the process that created the natural diamonds millions of years ago by exposing pure carbon to extreme heat and pressure.
The experiment was successful, and we got the first batch of man-made diamonds in history.
However, this process was very expensive. So, we had to wait a bit longer until the production of artificial diamonds was refined enough to go into serial production.
These days, these high goals are mostly met, and lab-grown diamonds are usually 50% to 70% cheaper than their natural counterparts.
This lack of gem market value – and the fact that lab-grown diamonds can be easily replaced and reproduced – make this artificial material ideal for industrial production.
Learn More: Lab-created Diamond Vs. Natural Diamond
3. Treated Diamonds
This group of diamonds consists of natural diamonds extracted by miners treated in specific and deliberate ways to enhance their look and increase their value.
Some of the common treatments include procedures like “filling” and color enhancements.
Also, we have to point out that all these steps are taken only if the gems can’t be sold at the market any other way, so their prices are dramatically lower than the ones you’d find attached to more refined pieces. You can look at them as a sort of “diamond aftermarket.”
4. Natural Fancy Color Diamonds
We purposefully separated this group of precious stones from regular natural diamonds because they, for all intents and purposes, represent an entirely different corner of the market.
So, what are natural fancy color diamonds?
Well, these are the diamonds that, due to some impurities in the original carbon material, feature a gentle but stunning hue.
Now, because they’re not 100% pure carbon and don’t retain all the physical properties of “clean” diamonds, you would assume that this group ranks very low on the market.
But you would be wrong.
What they lack in purity, natural fancy color diamonds more than make up for in terms of scarcity. They’re extremely rare; you’ll find only one colored diamond per 10,000 regulars.
We’ll deal with the available color options further down below.
Read Also: Recycled Diamonds: an Environmentally-friendly Gem Choice?
Types Of Diamonds Used In The Diamond Industry
The division we’ve covered above is relatively simple, intuitive, and easy to understand. As such, it is used mainly by laymen to navigate some basic turns at the diamond market.
But, as you can see, the strokes are comprehensive and based on different criteria. So, they’re of little use for people in the industry who need more precise data to sort out the pieces going through their hands.
So, this scale tries to fix these imperfections and give professionals something uniform, usable – but just as simple.
The criteria for dividing diamonds into groups are chemical impurities and structural anomalies that affect their market value as the most crucial point of consideration in this case.
Also, we’d like to point out that you can assign some diamond pieces with more than one diamond type, so the grading is not exactly 100% accurate. On the other hand, these marks are assigned and supervised by the Gemological Institute of America.
So, you’re probably getting the most accurate classification and certification possible.
And now, let us finally check the four main diamond types in this calcification.
1. Type Ia Diamonds
One of Type Ia diamonds’ most important physical and visual properties is that they emit a very noticeable yellowish hue. This pleasant color directly results from the relatively high presence of nitrogen clusters in the diamond’s crystalline lattice.
Without going too deeply into scientific jargon, these nitrogen molecules are able to absorb wavelengths on the blue end of the spectrum, so the light is reflected in yellow tones.
Although all this sounds very exciting, this neat light show drastically brings down the market value of Type Ia diamonds.
Also, we’d like to mention that this is an extensive group of precious stones, so the experts have come up with more precise grading.
So, Type Ia diamonds can be divided into two subgroups – Type IaA and Type IaB diamonds. The main difference between the two is that the latter contains aggregates of four nitrogen atoms – as opposed to two we can find in Type IaA. So, they appear even denser.
Neither one of these groups is capable of absorbing infrared or ultraviolet light, though.
2. Type IIa Diamonds
Unlike their cousins from the previous group, Type IIa diamonds feature no nitrogen impurities, no visible absorption, and varying fluorescence levels.
Furthermore, this group of diamonds was formed under exceedingly high pressure (much higher than the regular pieces), so the individual pieces usually feature irregular shapes.
But, these imperfections are easily eliminated through precise cutting, so, in the end, you get the most valuable and sought-after group of diamonds on the market.
That shouldn’t be that big of a surprise since investors and traders are usually driven by the exclusivity and scarcity of the material. And Type IIa diamonds make up only 1% of all diamond deposits in the world.
Then, there’s the fact that these precious stones feature no nitrogen impurities whatsoever, so they don’t absorb short-wave light. As a result, light can easily pass through the material, bounce back at the spectator’s eye and create an astonishing visual impression.
Aside from these most valuable colorless diamonds, the Type IIa group also includes fancy colored pieces that feature light pink, light blue, light yellow, light brown, light green, and light grey hues.
Since most of the diamonds belonging to this group were historically found in the Indian Golconda mines – the mines that produced the best-quality gems throughout XVI and XVII centuries – these pieces are sometimes referred to as “Golconda Diamonds.”
One of the most famous members of this family is the legendary Koh-i-Noor – a 105.6-carat behemoth that is now the most important piece of British Crown Jewels.
Suppose you’re willing to invest in Type IIa diamonds. In that case, you’ll be glad to know that the subcategory that is considered the purest and the most valuable pieces are marked with D color, no fluorescence, and VVS1 or IF clarity.
Related Read: Which Diamond Was Found In Golconda Fort?
3. Type Ib Diamonds
These diamonds are very similar to Type IIa diamonds in the sense that they make up only 1% of the global diamond deposits. But this is the point where similarities end.
Namely, Type Ib diamonds have rather prominent tinges of nitrogen atoms, but in this case, they’re not formed in some organized pattern. Instead, they’re scattered all throughout the crystal lattice.
That creates a stunning visual impression – and Type Ib diamonds usually feature bright, garish, and very intense colors. In most cases, those would be orange, brown, and yellow.
You can find the best examples of this type in canary diamonds and their most famous family member, The Incomparable Diamond, uncovered in the Democratic Republic of Kongo back in 1984. In its natural state, this beautiful yellow diamond weighed a whole 890 carats.
Other notable mentions are The Florentine Diamond, The Sun of Africa, and the Kahn Canary Diamond.
4. Type IIb Diamonds
Speaking in strictly chemical terms, Type IIb diamonds have an almost identical structure as the Type Ib group with only one slight distinction:
Type IIb traces a small presence of boron.
It may not sound like much, but these small particles make diamonds incredibly electrically conductive and lend them a very distinct blue or gray tint – and all the hues in between.
Once again, this visual appearance has simple chemical justification since boron can absorb the light at the red end of the spectrum.
Another interesting thing about Type IIb gems is that they’re scarce, making only 0.1% of available diamond deposits.
As you can probably guess, this scarcity packs Type IIb with a tremendous market value. One of the most famous Type IIb stones in the world is, of course, the fabled Hope diamond now stored in the Smithsonian Institute in Washington.
Explaining The Four Cs (And The Fifth One)
As we can see, the previous scale is used to describe the basic physical and chemical properties of the stones in question and, according to that, determine their overall marketplace.
Of course, these four main groups are too broad to tell us something more precise. After all, market-ready diamonds are processed products, and as such, have numerous other physical traits we need to factor in to determine their overall value.
These properties are described as four Cs or, to be more precise, carat, cut, clarity, and color. All of them can be used for ranking and organizing diamonds into various classes and groups.
But, before we start breaking down these terms one by one, we’d like to point out that, as of lately, a growing number of people use the fifth C – which stands for “conflict-free.”
The best way to describe the conflict diamonds would be as uncut diamonds extracted in the disputed areas of armed conflict and used to finance the war efforts of one or more sides in the said conflict.
Other terms used to describe these gems are hot diamonds, red diamonds, brown diamonds, or blood diamonds.
One of the best examples of these precious stones being used to finance war efforts can be found in Sierra Leone, where the rebel group called the Revolutionary United Front waged a civil war with the local government from 1991 up to 2002.
In the meantime, RUF used forced labor under the penalty of death and physical and psychological harm to obtain these diamonds.
In most cases, persons subjected to these atrocities were children.
A similar practice was noted in countries like Angola, Ivory Coast, Liberia, Guinea, and Guinea Bissau.
Several countries have issued various sanctions and policies whose overall goal is to prevent the trade of these conflict diamonds and discourage brutal practices used to extract them.
The two most important parties leading this movement are the USA and Canada. Adding the fifth C to the previous four is part of the efforts to encourage the trade of legally produced precious stones.
These so-called conflict-free – or ethical – diamonds have been mined and processed under legal labor practices, safe working conditions, fair pay, environmentally sound practices, and, most importantly, no human rights abuse.
Being produced in this manner, ethical diamonds also feature a higher market price.
Now that we have moved this grim but critical issue off the table, we can proceed to more technical terms like carats. Essentially, carat is nothing more than a weight unit used to describe the weight of the diamonds.
This measurement was introduced back in 1907 at the Fourth General Conference of Weight and Measures held in Paris. Why?
Well, diamonds are so scarce, small, and light. Using the traditional weight measures – both metric and imperial – doesn’t allow the necessary level of gradation we need to deal with objects of such a small mass.
So, at the beginning of the century, we finally got what we now know as carat or metric carat – since the basis for defining one carat was based on metric measures.
Today, one carat (ct) is a unit of mass equal to 200 milligrams or 0.00705 ounces as calculated with the imperial measurement system. Every carat is divisible into 100 smaller points weighing only 2 milligrams.
The word “carat” comes from the Greek word kerátion (κεράτιον), which means carob seed. The word entered the English language through its Italian form, carato.
These smaller carat points are actually called points. For instance, you will hear a lot about the one-point diamonds. It’s just something worth noting.
Of course, different cultures and nations have been using various measures to denominate the mass of precious materials. The most famous example we have to date is Roman solidus.
But, going back to the standardized metric carats, this mass measurement is used to divide all diamonds into various categories. Small unit weight also provides an excellent gradation, and present-day diamond scales can measure the stone’s weight to the fifth decimal place, which is incredibly precise.
The largest and the most valuable diamonds that are currently available are called paragons or paragon diamonds.
For all intents and purposes, these precious stones are considered to be perfect diamonds. To qualify for that title, they need to be without any flaws or inclusions and weigh at least 100 carats – or, in other words, 20 grams.
The largest diamond in the world, which carries the same name – The Paragon – is a D-color gem (more about that in a moment) that weighs 137.82 carats or 27,564 grams.
On the other end of the spectrum are the tiniest certified cut and polished diamonds produced by the Bhavani Gems (the diamonds are, hence, called Bhavani Micro). They consist of 57 facets and a total weight of no more than 0.0003 carats or 0.00006 grams.
In between these two extremes, we can find many different terms that jewelers and traders use to denominate diamonds based on their carat value – like one-carat diamonds, half carat diamonds, three-quarter carat diamonds, etc.
We’d like to finish this topic by reminding you that carat value alone is not a precise way to measure the value of a diamond or compare two pieces in any sensible way.
To be comparable, two diamonds with the same carat value need to:
- Have the same shape and cut
- Feature similar color and clarity
- Be graded by the same laboratory
Now it’s time to cover the other big C we use to rank the diamonds – and that would be clarity.
As the name suggests, clarity describes the absence of inclusions or blemishes that degrade the diamonds’ look and impede their ability to refract light the way we want to achieve through precise cutting.
So, let us not confuse this term with color that will be discussed later.
As we mentioned earlier in this article, diamonds result from a natural process in which carbon is exposed to tremendous heat and pressure deep below the Earth’s surface.
This very aggressive process can result in various internal characteristics we call inclusions – the presence of other materials in carbon – and external features we like to call blemishes.
The presence of these blemishes is not the only factor experts use to determine the so-called clarity of one diamond. Other physical and visual properties used to grade these precious stones are size, number, nature, position, and relief of these minor imperfections.
Of course, no recorded piece in history is perfectly pure; all diamonds feature some form of imperfections.
But, as we will see in the following breakdown, these minor blemishes shouldn’t be visible under a specific magnification level.
So, keeping that in mind, we can divide all diamonds into the following six groups:
- Flawless (FL) – The inclusions and blemishes are not visible even under 10x magnification
- Internally Flawless (IF) – No inclusions are visible under 10x magnification
- Very, Very Slightly Included (VVS1 and VVS2) – As the name suggest, the inclusions are barely visible but only to a skilled eye and under 10x magnification
- Very Slightly Included (VS1 and VS2) – In this case, the inclusions can be observed under 10x magnification, but they are not visible to the naked eye and can be considered minor
- Slightly Included (SI1 and SI2) – This group of diamonds is characterized by the inclusions that can be observed under 10x magnification
- Included (I1, I2, and I3) – Inclusions are easily observed under 10x magnification so much so they can affect transparency and brilliance
The following picture should illustrate the gradation, although the inclusions are, for obvious reasons, not accurately represented.
Although the differences can’t be visible in the picture, the differences between diamonds are often so tiny that they need extensive examinations to spot any variety in traits. For instance, VSI1 and SI2 diamonds will look virtually identical to the casual observer.
The main factors that are taken into consideration when grading the clarity of diamonds are as follows:
- Size – Generally speaking, the larger the inclusions they produce, the larger impact on the look of the diamond. However, the size of these inductions can also impact the durability of the stone in question.
- Nature – Not all inductions are the result of the same natural processes. For instance, some of them may look noticeable, but since they don’t penetrate too deep, they don’t present such a crippling drawback.
- Number – The rule of thumb here is the lesser number of inclusions across the diamond you have, the better. However, this rule can have exceptions if the blemishes are too small to be noticeable.
- Location – In this case, inclusions closer to the center of the diamonds have a greater impact on their clarity. On the other hand, inclusions closer to the griddle may be harder to see, but they can have a greater impact on the diamond’s durability.
- Relief – Last but not least, relief refers to the contrast inclusions crate against the body of the host diamond.
Now, it’s time to proceed to the topic that has very little to do with the diamonds’ natural properties and everything with the skills of the people treating them after mining.
We are, of course, talking about the diamonds’ cut, probably the best-known property after the mass expressed in carats.
This property is so important and appreciated because it has a tremendous influence on the diamond’s look and the ability to refactor light. Cutting, in turn, is a very demanding process that considers an entire range of factors like angles, proportions, brilliance, fire, scintillation, symmetrical facets, and various finishing details.
If any of these finishing works are performed with even the slightest imperfection, the value of the diamond will drop considerably.
The diamond won’t be able to sparkle, and it won’t feature the necessary level of brilliance – all the reasons diamonds have been in such demand since the dawn of humanity.
The GIA, an independent nonprofit organization that conducts diamond research and classification and education of gem professionals worldwide, provides the most reliable way of diamond cut certification.
But, the main task of this organization is grading precious stones. So, the gems that successfully pass this process are often called “GIA diamonds.”
But before we delve deeper into this topic, let us first try to learn a couple of terms we will use in this section. They are all illustrated in the image below:
And just one more important note: The diamond above pretty much represents the perfect diamond shape. If the diamond is too deep or too shallow, the angles’ cut won’t produce satisfying brilliance and fire.
You can see what we are talking about in the image below.
Keeping that in mind, the GIA scale divides all cut diamonds into five distinct categories:
- Excellent – In this case, the diamonds are pristinely cut. Their ideal proportions allow them to maximize sparkle, fire, and brilliance.
- Very good – These diamonds are truly beautifully cut, but not to the point when they earn an excellent mark. To the casual observers, they are very similar to excellent diamonds, but their slight imperfections do push them a whole grade lower.
- Good – Good diamonds pack a lot of sparkles, but they are usually disproportionate in one area or another. This is the point where diamonds leave the exclusive territory and aim more at the average consumer level.
- Fair – The point of precise cuts is to trap the light inside the diamond and let it fire up. In the case of fair diamonds, light is able to easily escape through the bottom and sides so they don’t truly create a spectacular visual impression. Because of that, jewelers seldom use them as center stones but rather as ornaments.
- Poor – As you can guess, poor diamonds feature the lowest cut quality and the lowest value. Fortunately enough, they are also very rare, so you can only find them in very shady dealerships. Reputable diamond traders and jewelers only work with the diamonds rated with the mark fair or higher.
Now, this is a good opportunity to address one more common question asked by countless newcomers to the world of diamonds.
If there is a grade that describes diamonds as “excellent,” then what are brilliant diamonds?
Well, “brilliant” is not so much a grade as the type of cut. The so-called brilliant diamonds are cut in such a manner to maximize the diamond’s brilliance. Brilliant diamonds are always cone-shaped and produce maximized light return through the top of the diamond.
The illustration of one brilliant diamond can be seen in the image below:
The brilliant-cut was invented back in 1919 by the Belgian diamond cutter Marcel Tolkowsky. Since then, it has become a gold standard for prestige.
Aside from the beautiful look and the stunning light show these stones produce, one of the main reasons why brilliant diamonds are so renowned is because this process cuts down the diamond’s overall volume.
Turning an original stone into a brilliant diamond means you have to lose at least 50% of its original carat value. That is simply extraordinary.
Of course, the brilliant-cut may be the most well-known and the most renowned type of cut – but it is far from being the only one.
So, we get another intuitive way to split diamonds into different distinct groups. For instance, another trendy cut is the step cut which creates a very symmetrical shape in which most of the angles are parallel to each other.
Other popular diamond cuts can be found in the image below:
And now, it’s the time to tackle the last of the big four Cs – the color of the diamond.
In the previous sections, we’ve seen that some diamonds with strong colors or hues earn very high marks – and even higher market value.
These marks primarily take into consideration the chemical composition of precious stones in question. Once again provided by GIA, the color grading scale deals primarily with diamonds with or without nitrogen impurities.
So, the precious stones are ranked on the scale from entirely transparent to those with a strong yellow hue.
The diamonds that are the purest and feature no color hues are marked with the A grade. On the other side of the grading spectrum, we have the diamonds decorated with the Z grade with a noticeable yellow hue.
See Also: Do Diamonds Turn Yellow With Age?
Here’s a simple picture that should give you some visual reference for the ranking criteria:
So, it’s obvious this grading scale uses the English alphabet as its basis. Where are the letters A and B?
The answer can be found in the simple fact that the color grading methods used before GIA standardized the whole thing was all over the place and didn’t use any uniform criteria to rank the color of the diamonds.
So, you had various A’s, AAA’s, and even AAAA’s that were used with no rhyme or reason.
To avoid confusion and put these obsolete ranking methods to rest, GIA eliminated A’s and B’s. It’s as simple as that.
The only thing left to answer is how GIA ranks the diamonds and assigns them with these letters. As we can see, the gradation is very precise and takes into consideration even the slightest possible diamond hues.
To ensure that the diamonds have a fair and precise examination, they’re treated with light rays in the controlled lightboxes to get the best possible results.
Of course, all light sources are calibrated to Liddicoat’s standards, with professional microscopes observing the resulting wavelength dispersion.
So, it’s not simply a matter of visual observation. We’re talking about real science put to practical purpose.
Related Read: What Is A Composite Diamond?
Last but not least, we would like to point out that, aside from the four main C’s, GIA uses one more vital parameter to rank the examined diamonds.
That would be the diamonds’ proportions.
Much like other rankings and divisions we have covered in this article, this grading relies on several different criteria. Once again, we will throw in an image for a quick visual reference:
Now, let’s proceed to the short diamond proportion breakdown.
Diamond Table Percentage
This parameter is calculated by dividing the width of the diamond’s top surface area (table) by the width of the stone.
For instance, if the diamond’s table facet scores the width of 4 millimeters and the overall width of 5 millimeters, we will say the diamond table percentage is 80%.
This one is very simple – diamond width describes the width of one diamond from one end of its griddle to the other. Essentially, it is the diamond’s diameter when observed from the top.
We’ve already briefly touched upon this topic in the previous passages, but it’s worth reiterating:
Diamond depth refers to the diamond’s height from the culet to the top of the table. The depth of one diamond is calculated by dividing its depth by its width and is expressed in millimeters.
And, for instance, if the said diamond features a depth of 4 millimeters and width of 4.5 millimeters, you’ll get the percentage of 88.8%.
Although when you compare two diamonds with the same carat values, the one with a lower depth percentage appears larger due to increased width, the diamonds that push this percentage too low can appear much darker since they don’t reflect the light just as well.
So, you get an overall idea:
The point of all these percentages and rankings is finding the diamond proportion that provides the optimal light dispersion, fire, and all other visual effects covered above.
The Way The Diamonds Are Formed
Finally, the last way to divide diamonds into distinct groups and sort them out is based on their initial formation.
Now, if you want to turn pure carbon into its purest diamond form, you need a pressure of about 45 to 60 kilobars (50,000 more than the Earth’s atmospheric pressure) and a temperature of 900 to 1,300 degrees Celsius.
Putting aside the controlled lab environment where we can emulate these conditions ever since the 1950s, nature provided more than one way to turn carbon into the most valuable material on Earth – well, aside from dark matter.
Deep Source Eruptions
We’ve briefly mentioned this origin story earlier in the article. Still, it’s worth going over the story again since deep source diamonds make the vast majority of natural diamond deposits on the globe.
So, some 2 billion years ago, deep within the Earth’s mass – some 200 kilometers underneath the Earth’s surface – violent geological circumstances compressed carbon in its pure crystal form.
These diamond deposits were later brought closer to the mantle by the violent eruptions of the so-called Kimberlite pipes. You can read more about this in our other articles.
The term “subduction zones” refers to the areas where Earth’s tectonic plates violently interacted with each other.
The subduction part comes from the fact that one of the two plates – usually the one covered with oceans – is submerged underneath the other during these collisions. And as you can guess, these clashes also create the conditions necessary for the formation of diamonds.
Meteorites are debris of various space objects – like comets and asteroids – that travel through space, enter the Earth’s atmosphere, and then violently land on the planet’s surface.
If the meteorite features sufficient mass and the impact area is rich in carbon, the impact can produce diamond deposits.
Finally, various objects flying through space tend to experience quite a lot of collisions before they find a way to the surface of our planet.
Since other planets and space objects can also contain rich carbon deposits, these violent off-world impacts can also produce the circumstances required for the formation of diamonds.
We hope this breakdown of all the important ways we can rank, divide, and organize different diamonds will help you navigate the complex and often intimidating world of these precious stones.
The love affair between humanity and diamonds is a couple of thousands of years old. People have used countless ways to determine which diamonds are the most beautiful or score the highest value during this incredibly long period.
However, you shouldn’t be scared by this disparity.
Over time, most of these criteria became standardized, and now, ranking and rating diamonds requires only a bit of research. We hope this article will help you along the way.