Clarity of a diamond is very easy to understand and evaluate than all other Cs of a diamond. As the word itself says, clarity is a diamond's purity. In other words, clarity is a diamond's ability to let the light enter in a diamond and reflect its brilliance.
It can be only seen by the powerful microscope or jeweller's loupe only. Generally, it does not affect the beauty or appearance of a diamond. To understand clarity, it is necessary to understand inclusions and blemishes in or on a diamond. Inclusions are interior irregularities while blemishes are exterior irregularities. These imperfections can be seen in almost all the diamonds in more or less amount.
During its formation in the earth, inclusions like air bubbles, cracks and other non-diamond materials are found within a diamond.
It disturbs the dispersion of light and can diminish the diamond's brilliance especially large inclusions. It also reduces the life of a diamond by reducing its resistance to fracture. Coloured inclusions can also affect the appearance of the diamond. Inclusions reduce the value of a diamond.
If inclusions are the impurities within the diamond, blemishes are imperfections on its outer or exterior surface which includes scratches, pits and chips. It generally comes into existence while cutting and polishing of a diamond. However, it can be eliminated or polished away with re-cut under the supervision of experts.
However, blemishes have little or no impact on a diamond's appearance, value and beauty as they rarely affect the durability and structure of the diamond.
Clarity of a diamond can be examined with a 10x magnifying microscope and imperfections can be detected easily by the experts. Inclusions can affect the grade of a diamond more than the blemishes. Larger, darker and deep marks can significantly affect the grade of the diamond.
The Gemological Institute of America (GIA) has developed an International Diamond Grading System, which is widely recognized worldwide for its simplicity and effectiveness. In this system, a diamond's clarity can be classified based on the size, position and nature of its inclusions and blemishes. The list below explains the grading system very well.
Diamonds fall under this category has no inclusions or blemishes detectable with 10x magnification and are exceptionally rare.
It is very valuable and beautiful scenario in which there are no inclusions found in the diamond. However some surface blemishes have been found with 10x magnifying microscope.
Diamonds fall in this category have inclusions and blemishes which are extremely difficult to notice for a even a skilled grader.
These diamonds have inclusions and blemishes which can be noticed by microscope, but not with naked eye and do not affect the beauty, appearance and value of a diamond.
Diamonds include inclusions and blemishes which are noticeable by microscope as well as naked eye.
Alike SI1 and SI2, these diamonds contain inclusions and blemishes noticeable by naked eye and also can harm the beauty and value of the diamond by negatively impacting the brilliance of the diamond.
It will be best if you choose a diamond which falls under the FL and IF categories. Nonetheless, your budget is also a concern while choosing a diamond. In the diamond market, flawless graded diamonds are considered a most valuable diamonds as it is rarely seen.
You also can choose diamonds which are eye-clean diamond- a diamond that has no imperfections visible by the normal eye- as they also considered valuable diamonds.