Clarity refers to the existence of apparent interior and exterior characteristics in a diamond.

Some of these happen naturally and some happen because of the pressure put upon the diamond during the course of mining. inside characteristics are called inclusions and outside characteristics are called blemishes. Clarity characteristics guarantee that no two diamonds are entirely similar. Many gemologists refer to characteristic of clarity like a diamond's fingerprint. Gemologists can use clarity characteristics to differentiate between natural diamonds and fakes, or to identify stolen or "exchanged" diamonds by comparing them to a previously recorded plot or picture. These are just some of the more common inclusions and blemishes found on diamonds clarity is graded on a scale that ranges from Flawless to Imperfect.

To – this day even with all the advancement of technology, grading at the renowned gemological grading labs is only performed humanly. In the case of the GIA, the individual opinion of at least two extremely expert gemologists is used, with each of them separately applying a clarity rating. Diamonds with borderline or divided grades are brought graded again by an additional expert gemologist (or graders) and the grade is then determined by the majority opinion. It is very important to keep in mind that a diamond's clarity grade is established in most advantageous laboratory lighting surroundings and with highly accurate gem microscopes that vary in magnification from 10 times and even up to  70 times. Diamond expert gemologists are constantly taking into account the following five aspects of clarity characteristics when determining a clarity grade: the size, the number of, the position of, the type of, and the color.

The GIA Grading Scale for clarity is separated into 11 grades.

Flawless diamonds are exceptionally rare and therefore very highly valued. Most people never even get to see a flawless diamond, besides for in a museum.

Internally Flawless diamonds are also very rare and because they also have no internal inclusions, but they do have some minor blemish that could sometimes be detached through polishing.

VVS1 and VVS2 diamonds contain tiny inclusions that are difficult even for experienced gemologists to detect under 10 times enlargement.

VS1 and VS2 diamonds contain slight inclusions which can be seen with a little effort under 10 times enlargement.

SI1 and SI2 diamonds include visible inclusions which can be seen under 10 times magnification. Generally, SI1 inclusions are not visible when they are face-up without magnification. Most fanatical observers may begin to detect eye-visible inclusions in diamonds which are face-up of SI2 clarity, even without magnification.

Diamonds in I1, I2 and I3 clarity range include inclusions that are noticeable under 10 times magnification. I1 and I2 inclusions are often evident to the inexperienced eye and may affect clearness and as an outcome diminish the diamonds brilliance. I2 inclusions may also affect a diamond's toughness. I3 diamonds often do not have clearness and durability.

BLEMISHES - These take place on the face of a diamond and are usually a result of the atmosphere that the diamond has been exposed to either in nature or during the mining procedure.

1. Extra Facets - When an inclusion is near the surface this cut is made to eliminate it in order to raise the diamonds general value. Many times, they do not affect the clarity grade but the naked eye usually canot or at least finds it very difficult to detect in most cases.

2. Naturals - This is a small piece of the original rough diamond's exterior which was left on the polished diamond. These are blemishes, but they might also be considered as a mark of expert cutting; the occurrence of a natural reflects the cutter's skill to design a stunning polished gem, while still keeping as much of the original diamonds weight as possible. Many times, naturals do not affect the clarity rating. In most cases, they are invisible to the bare eye.

3. Surface Graining - This is a natural occurrence that causes blemishes while the diamonds grow. It does not precisely occur on the diamond's surface; it is an integral part of the stones makeup and most likely cannot be detached from the diamond without causing at least a little weight loss.

INCLUSIONS - are certain characteristics that happen inside the diamond itself. Almost all interior inclusions are naturally happening.

1. Included Crystals - a mineral crystal within a diamond - they were absorbed while the diamond was growing. Some are see-through and some have color, depending on what kind of crystals they are underneath a microscope they frequently look like little round soap suds. These are usually unnoticeable to the bare eye.

2. Pinpoints - These are included crystals that are so extremely minute that, even when magnified 10 times, they still only look like a small dot. They can sometimes be very difficult to find.

3. Needles - These look like exceptionally slight minute needles even under a microscope.

4. Knots - A knot is an included diamond crystal that comes all the way from the inside to the face of a polished diamond.

5. Chips - These are a small, very thin notch on the surface of the diamond. This could be a natural occurrence that caused the opening in the diamond, or it could be that it was created when removing a minute crystal or while cutting the diamond itself.

6. Cavities - These are a larger version of chips. These are sometimes deliberately created by the gemologist while doing the cutting, when finding an included crystal close to the surface of the rough diamond and removing it, this sometimes leaves this cavity behind.

7. Feathers - These are small fractures in a diamond. Stress is what usually causes them while the diamond was still growing. This can occur on the inside of the diamond or on the surface. The expression "feather" comes from the idea that, when seen under a microscope, these fracture often appear to have an imprecise, feathery shape to them.

8. Internal Graining - This is a naturally happening occurrence in some diamonds. This usually occurs within the diamond is still not mined .

9. Clouds - Clouds are actually a cluster of a number of exceedingly minute inclusions that are too small to be noticeable from one another, even when magnified under a microscope, that’s why they are called clouds because this cluster a lot of times looks like a soft see-through cloud within the diamond.