Clarity is an indication of a diamond’s purity. It describes quite literally the degree to which a diamond is free of imperfections. The clarity grades range from internally flawless (IF) to highly imperfect (I3).
Internal flaws in diamonds include are called “inclusions” while external flaws are called “blemishes.) A blemish is usually a feature of the cutting or polishing of the stone, but can also be a scratch or chip. Most blemishes are so small as to have no effect on the beauty or brilliance of the stone. Inclusions are generally small, sometimes microscopic, imperfections inside the diamond. In all diamonds, except the very rarest, the laboratory will find some inclusions. They are often caused by disturbances in the crystallization process, or by traces of minerals, gasses or other materials which were trapped inside the diamond. They can even be minute fractures which may have occurred millions of years ago. Inclusions may look like tiny crystals, clouds, or feathers or black spots, and are unique to every diamond. Many of these birthmarks are not visible to the naked eye. In fact, it is very rare to find a diamond that is completely clean to the expert eye using magnification.
The clarity of a diamond is graded by how many, how big (relative to the size of the stone) and how visible the inclusions are, and where they are located within the diamond. The fewer and smaller the inclusions, the more rare and valuable the diamond. Less than 1% of all diamonds ever found have had no visible inclusions and can be called internally flawless (IF).
Abbreviations in Clarity Grading
A diamond’s clarity grade is described using the following universally accepted abbreviations.
Flawless – Internally Flawless
Flawless stones have no external blemishes or internal inclusions when examined by an experienced grader using 10X magnification. Internally Flawless diamonds have no inclusions under 10X magnification but may have some minute external blemishes.
Very, Very Slightly Included
Contains minute inclusions that are difficult for even experienced graders to see under 10X magnification.
Very Slightly Included
Clean to the naked eye; contains minute inclusions when examined under 10X magnification.
SI1, SI2, SI3
Ranges from clean to nearly clean to the naked eye (eye clean) when viewed from the top.
I1, I2, I3
Ranges from being nearly eye clean to having very easy to find imperfections to the naked eye which might affect the brilliance of the stone.
Clarity Impact on Beauty and Price of Jewelry
Impact on Beauty: The clarity grade of a diamond may have little or no effect on the beauty of a diamond if the clarity grade is within the first six or seven grades (Flawless-SI1 or sometimes even SI2.) Most people can’t see much visible difference among stones until reaching the “imperfect” grades. Please keep in mind that earrings and pendants do not generally receive the same scrutiny as the feature diamond in a ring. For that reason, you might consider sacrificing a little in clarity in exchange for greater size.
Impact on Price: As in color, small differences in clarity can have a great impact on price. If beauty is the chief concern, it is advisable to stick with a well-made (well cut) diamond of SI1-2 clarity or better. Within your budget, try to arrive at a good balance between overall quality and size.