VS Diamond vs SI Diamond: Which Should You Choose?

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If you’re researching buying a diamond, you’ve probably already narrowed down the clarity grades you’re looking for to the Goldilocks zone of VS and SI: not too expensive but not full of ugly spots you will see every time you look at your diamond either.

That’s why VS, or very slightly included, and SI, or slightly included are the most popular clarity grades. But you still have to narrow it down a bit more. Each one of these grades is broken down into two levels: VS1 and VS2 and SI1 and SI2.

Although all four VS and SI diamond grades are technically “eye clean,” or with no easily seen inclusions face up, in practice, some of these diamonds look a lot better than others.

Don’t worry, we’ve gathered everything you need to know about VS and SI diamonds in one (maybe a little long) blog post. Read on to get the bottom line on VS1 diamonds, VS2 diamonds, SI1 diamonds, and SI2 diamonds so you’ll know exactly which one to choose for your diamond engagement ring.

VS1 Diamonds: Clean Dreams

No doubt about it, VS1 diamonds look great. Even under 10x magnification a VS1 diamond will probably look like it’s flawless to someone who’s not an expert. (Diamonds that are graded VS1 have minor inclusions that are difficult to somewhat easy to see for a skilled grader using 10x magnification.) For civilians like us, that means you will look at a VS1 diamond with a loupe for a long while before you manage to see even one speck.

VS1 diamonds don’t have high relief inclusions like black spots in the center of the diamond or inclusions that cause durability issues. You definitely won’t see the inclusions in a VS1 diamond with the naked eye. It’s hard to find an example of a VS1 diamond where you can even see the inclusions in a large rotating video! And you definitely won’t see them when your VS1 diamond is set in an engagement ring.

But for most people, VS1 is overkill. It’s beautiful but you will usually pay more than you really need to get a beautiful diamond.

RockHer’s diamond-picking artificial intelligence, ROSI, often does recommend VS1 diamonds, especially for fancy shapes cuts like emerald cut diamonds and Asscher diamonds that have broad facets that show inclusions more easily.
You also may want to upgrade to a VS1 clarity diamond if your carat weight is larger than two carats, because inclusions are judged proportional to diamond size. It’s easier to see the inclusions in larger diamonds. But the rest of you can move on.

VS2 Diamonds: The Best Balance

For most people, VS2 is the sweet spot. Diamonds that are graded VS2 have a few more minor inclusions that range from difficult to somewhat easy to see for a skilled diamond grader using 10x magnification. Generally VS2 diamonds will have many tiny inclusions or one or two larger inclusions.

You generally won't see the inclusions in a VS2 diamond with the naked eye (unless you blow up the image of your diamond larger than a golf ball.)

ROSI recommends VS2 diamonds for most people because the inclusions are so minor that that don’t affect the beauty of your diamond at all when it’s set in an engagement ring but this clarity grade costs less than the top clarity grades. You don't look at your diamond with a loupe so why not save some money by accepting a few inclusions you can’t see without it?

SI1 Diamonds: Good Deals

SI1 diamonds are a bit more of a gamble. Here’s why.

When you look closely at a diamond with an SI1 clarity grade, you will probably notice at least one inclusion. SI1 clarity diamonds have noticeable inclusions that are easy for a skilled diamond grader to see using 10x magnification.

There are some good looking SI1 diamonds, especially when you have a diamond picking AI like ROSI evaluating the inclusion size, position and type. If you are careful, you can find SI1 diamonds that have the right kind of inclusion in the right place to be eye-clean. ROSI looks for transparent inclusions that are inconspicuous, even if they are large, or lots of pinpoints that are too small to be seen.

Make sure you eliminate SI1 diamonds with chips, cavities, knots, etched channels, or manufacturers remnants because they affect a diamond’s beauty and durability too much. Also eliminate diamonds that have a feather inclusion in the corner or point of a fancy shape, which may be a durability issue.

But if you take the time to really weigh the inclusions in an SI1 diamond, you can find a beautiful diamond that’s a great value too.

SI2 Diamonds: Risky Business

Here’s where we think you should definitely draw the line. GIA graded SI2 diamonds have noticeable inclusions that range from easy to very easy to see for a skilled grader using 10x magnification. You will definitely be able to see the inclusions in an SI2 diamond with the naked eye if you look carefully. We’ve certainly seen SI2 clarity diamonds that are beautiful. But we’ve also seen many SI2 diamonds like this.

If your diamond has a big black inclusion right in the middle, it will always look like it needs to be cleaned. Once you see it, you can never unsee it.

And although diamonds with inclusions in the center of the table are the easiest to see, SI2 diamonds with inclusions near the pavilion can have reflections like a hall of mirrors so you see a single inclusion more than once. Some SI2 diamonds, like the stone above, have both of these things.

If you are on a limited budget, SI2 can be an option but you need to tread carefully. Look for SI2 clarity diamonds with transparent inclusions, even if they are large. Eliminate SI2 diamonds with chips, knots, etched channels, or manufacturers remnants and inclusions in the corner or point of a fancy shape, which may be a durability issue.

Let’s face it, you can find SI2 diamonds that are much more beautiful and a better value than the diamonds sold at chain jewelry stores and mass merchants. Most chain stores carry Included or I clarity diamonds, (often with reports from no-name labs that call them SI diamonds.) If you select a GIA graded SI2 diamond carefully, you can find a nice-looking diamond at an excellent price.

The Bottom Line: We Recommend VS2 Diamonds

We think that diamonds with VS2 clarity grade offer you the best balance of beauty and affordability because you won't see the inclusions in a VS2 diamond with the naked eye. In general, the tiny differences in appearance between the top grades of the GIA clarity grading scale are worth the investment.

But you may want to upgrade to VS1 for diamonds that are larger than two carats or emerald cut diamonds and Asscher cut diamonds that have broad facets that show inclusions more easily.

If you are buying a round brilliant diamond, finding an eye-clean SI1 diamond may be a good choice for you. Remember to insist on a grading report from the GIA or AGS in order to insure that your diamond actually is an SI1 and not a lower clarity grade: other laboratories may not grade to the same high standards.