Before we get into it, lets quickly recap the definition of clarity. When a diamond forms in nature, it slowly expands and starts to pick up on little things around it. Those impurities, in turn, get caught in the diamond and, therefore, become a part of it. The more impurities and imperfections that exist in the diamond, the less rare, hence the less expensive it becomes. A diamonds clarity is graded based on the imperfections or impurities that a diamond may or may not possess.
For reference, here’s the clarity grading scale:
IF (Internally Flawless)
VVS1 (very very slightly included 1)
VVS2 (very very slightly included 2)
VS1 (very slightly included 1)
VS2 (very slightly included 2)
SI1 (slightly included 1)
SI2 (slightly included 2)
I1 (imperfect 1)
I2 (imperfect 2)
I3 (imperfect 3)
“SI” stands for ‘slightly-included.’ The ‘slightly-included’ group includes two clarity grades, SI1 and SI2. Generally, my recommendation when diamond shopping is to focus on the aspects of a diamond that are visible to the naked eye. For example, because the carat weight and the color grade of a diamond are two visual components that one can differentiate to the naked eye, it makes sense to try and maximize those two components, white still being budget conscious. On the other hand, clarity is the one aspect of a diamond that you can’t actually differentiate to the naked eye (usually not the case in the ‘imperfect’ category). Even more than that, according to the GIA standards, any diamond in the slightly included (SI) category and above, should be completely eye clean. Yes, imperfections may exist in the diamond, but no, you should not be able to see them to the naked eye, nor should it have any effect on the sparkle and brilliance of the diamond.
Here’s a common misconception. Very often, when working with a client for a diamond engagement ring, the client will request to be at the VVS (very very slightly included) or VS (very slightly included) clarity, without even considering the SI (slightly included) category. The reason for that is because when doing some initial research, they come across magnified images of diamonds in the SI category that portray various imperfections (black or white markings). Seeing those imperfections up close becomes a huge turn off, especially because they think they can actually see them to the naked eye. The reality is that those imperfections they’re seeing online (heavily zoomed in) can’t actually be seen to the naked eye. At the end of the day, that’s what I yearn to stress. Yes, imperfections can exist in the diamond, that’s okay! You just don’t ever want to be able to see them to the naked eye. The SI category is that perfect middle ground where you can feel good about not hurting the quality or sparkle of the diamond, but also giving in just enough to possibly go bigger in size or better in color (two qualities in a diamond actually visible to the naked eye).
Here’s a hypothetical scenario for you—let’s say I put three diamonds in front of you. All three diamonds have the exact same carat weight and color grade, the only difference is one is a VVS1, one is a VS1, and one is an SI1. You (nor I) should be able to see any noticeable differences to the naked eye. Under a 10x magnification lens (jewelers loupe), you may be able to see the differences, but to the naked eye, no shot. Hence, does it make sense to spend thousands of dollars more towards something you can’t actually see?!
Just to clarify—I’m not saying to only focus on the SI’s. My point is to not immediately eliminate that as an option because of something you may have read or seen on Google. If you still don’t feel comfortable at the SI category after examining a few options, that’s completely fine. At least you gave it a chance.
Please note—this general rule of ‘giving in’ on clarity ONLY applies to brilliant cut diamonds (any diamond shape that has multiple facets cut in various directions). The one exception to this rule is the step cut diamond, a.k.a. the emerald cut and assher cut diamonds. Because the emerald cut diamond and the assher cut diamond resemble looking into a mirror, most times, if you do explore options below a VS2, it is very possible and very likely that you’ll be able to see those imperfections to the naked eye. So, if your significant other has their eye on a step cut diamond, you don’t have as much leniency to give in on clarity.