Diamond Clarity Grades
The GIA considers various factors when grading the clarity of a diamond. They will magnify all diamonds by 10x and then look at the position of the inclusions as well as the number of them, their size, reflectivity, and colour.
The grades are as follows:
Flawless Diamonds (FL)
These diamonds are exceptionally rare, in fact, only around one in every 5,000 diamonds have a flawless grade. This means that there are no blemishes or inclusions, even under magnification.
Internally flawless (IF)
IF are extremely similar to FL, there are only a few tiny differences, which can only be viewed by a skilled grader under magnification.
Very slightly included (VS1 and VS2)
Again, inclusions are not visible to the eye. They are clearly visible under magnification but they are minor.
Slightly included (SI1 and SI2)
Now we get to the stage where inclusions become visible to the untrained eye in some cases on close inspection.
Included (I1, I2, and I3)
Finally, I1 diamonds feature blemishes that everyone can see. I2 and I3 diamonds can feature pronounced inclusions to the point where the durability of the diamond is compromised.