VS2 vs. SI1 diamonds
Understand the difference between SI1 and VS2 diamonds, and when you should choose one over the other
‘Slightly Included’ is the diamond clarity grade scale below ‘Very slightly included’ on the clarity scale, and their description is:
Slightly Included (SI1 and SI2) – Inclusions are noticeable to a skilled grader under 10x magnification
SI1 diamonds are the higher grade in the slightly included grading band, which means that their inclusions are more difficult to detect than the SI2.
What does a SI1 diamond look like?
As with a VS2 diamond, there is can be a great deal of variation in SI1 diamonds. Check out the two stones below:
As you can see, there is a clear difference between the two.
The SI1 diamond on the left has inclusions that are clearly visible, and should be avoided.
The SI1 diamond on the right is likely to present as eye clean, and should be considered, if other factors with the stone (cut, pricing) are favourable.
When should you choose an SI1 diamond over a VS2 diamond?
If you can view high quality images of diamonds and can find an eye clean SI1 diamond then it is a great option. It will be less expensive and look identical when viewed in a ring.
However, finding eye clean SI1 diamonds that also have a high quality cut that is optimised to deliver as much brilliant sparkle as possible can take a little while. If you’re prepared to wait a while to find the perfect stone though, they can be a great choice.
When should you not choose an SI1 diamond over a VS2 diamond?
If you can’t see a high quality, magnified image of a SI1 diamond, or if you can’t inspect it in person then you shouldn’t consider it for purchase. You would be taking too large a risk that it would not be eye clean.