When a beautiful natural diamond forms underground under high pressure and temperature for thousands of years, rarely under ideal conditions, it is common for them to have birthmarks called inclusions or imperfections. Although some can only be seen under magnification, there are certain Diamond inclusions to avoid as they really compromise the aesthetics and durability of the rock.
If you wish to acquire a beautiful diamond, it is ideal that you know how to recognize them.
Inclusions and imperfections can occur in a diamond for many reasons and in many different patterns. Most of them are created at the time of its formation. Experienced diamond cutters know how to work the stones so that inclusions have a minimal impact on their aesthetics.
Some inclusions can be other minerals, smaller diamonds that were absorbed by a larger diamond, gas bubbles or even uncrystallized carbon residue.
Depending on the amount, pattern, color, location and impact on the aesthetics of the diamond, its clarity level is defined.
The higher the clarity level (less imperfections) the higher the value. If you want to learn more about diamond clarity, visit our advanced guide on the subject. Diamond Clarity
Since some inclusions are harmless and cannot be seen unless inspected by a jeweler with a 10x magnifying loupe, some prefer to go for lower clarity levels to opt for larger stones. Although you should be careful as some inclusions are really inconvenient and problematic.
There is an extensive list of possible inclusions in a diamond, but the most well known are:
Some imperfections or inclusions can be created, such as laser marks. Other inclusions such as clouds, for example, are formed when many points converge in one place. This makes defining all inclusions a... extensive task.
What are the worst inclusions in a diamond? Generally speaking, any that are visible to the naked eye, but the worst are:
Chips are fractures in the diamond, usually found in the top layer of the diamond. They are usually synonymous with mistreatment, wear or a cutting accident, which in addition to compromising the aesthetics of the stone also damages its integrity.
A crack considerably reduces the diamond's resistance and tends to spread easily with any strong blow.
If you are interested in acquiring a diamond, even if your eye is not trained, try inspecting it with a magnifying glass or use your fingernail to scan the girdle (thin lateral edge of the diamond) for a potential fracture.
If inspecting a disassembled diamond, be sure to check the sensitive parts of the cut such as the sharp corners (if present), the culet and the girdle. Remember that a setting can be used to cover a chip or crack, so pay double attention on used jewelry that is in a mounting.
If you have found a good deal on a diamond with a surface chip, a professional diamond cutter can "re-cut" the diamond until the flaw is removed. This will remove some of the weight (and its value) but increase its durability.
Some diamonds can trap other nearby crystals, small diamonds or traces of carbon that have not yet crystallized. These inclusions within the diamond are known as crystals and dots.
Crystals and dots can be of many colors, including black and white.
If the dots are actually white, they are difficult to see with the naked eye, even under magnification. But if the carbon or crystal is dark, it can become a problem.
Although these inclusions do not affect the integrity of the diamond, they become increasingly visible as they approach its outer center. Of all the potential inclusions, these are the most conspicuous, some may even interfere with the bounce of light diminishing its scintillation and attractiveness of the diamond.
Feathers are literally internal fractures in the diamond, which like chips, compromise its integrity, durability and strength. These are rarely colored, so they are usually very easy to disguise in a cut diamond, but as they get longer they become more obvious and problematic.
Long feathers damage the aesthetics and quality of the diamond, interfere with the brilliance, and leave the stone vulnerable to knocks. If a fracture is too close to the surface it is a potential breaking point.
Diamonds with very long feathers, sometimes called line cracks have a much lower value in the market, even with good color and cut levels, but represent an investment risk because they will break with any hard hit.
Cavities are hollow structures that form on the outside of the diamond when a crystal or solid inclusion is removed during cutting/polishing.
Cavities have to be carefully evaluated because, although they are found in the edges and folds of the diamond, they are not always so evident. At this point, it is very important to consider the gemologist's evaluation.
Cavities in diamonds graded with a VVS clarity level are tiny grimaces compared to those in an SI diamond. The latter are probably visible to the naked eye and pose a risk to the durability of the diamond.
The real problem with cavities is that they are excellent places to accumulate dirt, so if neglected they can obscure part of the gem.
Laser marks are'nt natural inclusions, that is, they are created by human grace. They are formed when an expert uses a laser to discolor or remove a dark inclusion from the diamond, leaving a white line from the outside that is difficult to see.
Keep in mind that much of the value of a gemstone is precisely how difficult they are to get naturally in their "purest" state. If a person modifies the clarity of the diamond they are modifying its status as a natural gemstone, which diminishes its value.
Modified and lab-created diamonds are traded in a different market than natural diamonds. Take that into consideration.
Many natural inclusions are harmless, some are left in on purpose to make the gem larger or not to compromise its structure. This is the case with natural indented inclusions.
A natural imperfection is usually left in the girdle of the diamond and is almost never seen. It is merely part of the original skin of the rough diamond that is left unpolished because doing so would sacrifice more material.
Natural indented, are inclusions that go deeper into the diamond. In both cases, they are left on purpose. They are simply the fingerprints of a diamond.
You don't have to view inclusions as enemies, nor obsess over them. Most require a high magnification loupe to see, as long as you prefer suppliers with high quality standards such as Albert Hern.
Look at your diamond, consult its clarity certificate and decide for yourself if the patterns look interesting to you. As long as they are clean to the eye, they will rarely give problems.
It is important to know What inclusion to avoid in a diamond when you want to go for much cheaper gems that optimize your budget. In this case, knowing what kind of imperfections are preferable is a great help.