Is There Such A Grade As SI3 Clarity? August 7, 2018 – Posted in: Jewelry Blog

Grading diamonds are both objective and subjective – and knowing that will help you greatly when trying to understand the deal with SI3. The search for flaws and inclusions is the objective part, they’re either present or they’re not. The subjective part is when the clarity of the diamond comes to actually be given.

Although it should be consistent, the fact is that those doing the grading may not see the same things. Or they may see the same things but then give different grades for identical diamonds. The short answer to what can be done about that is actually “very little”.

Fortunately, most experts will come to broadly the same conclusions.

Scroll to the bottom to listen to our new podcast about SI3 Diamonds. Get the full perspective on SI3 Diamonds!

GIA Clarity Grades

GIA D Color Diamond in UV Seal
An example of a D color VS1 clarity GIA certified diamond

The Gemological Institute of America is the body who first determined the clarity scale of diamonds. It is this scale that all report issuers use as the basis for the grade they give to a diamond. They go from Flawless (F) to Included level 3 (I3). As might be expected, F clarity has no visible inclusions and I3 has some that may even be visible without magnification.

Diamond Clarity Scale: F – IF – VVS1 – VVS2 – VS1 – VS2 – SI1 – S12 – ??? – I1 – I2 – I3

In amongst the rest of the grades are SI1 and SI2 or Slightly Included levels 1 and 2. This is the group just before we reach the Included (I) group. By the time we reach this point on the scale, inclusions are likely visible to the naked eye. If not, it is increasingly likely that the brilliance of the diamond will suffer from reduced light reflection.

Occasionally, we will see the grade SI3 used to describe the clarity of a particular diamond. So what does SI3 mean?

What is Slightly Included?

Examining emerald with a Loupe

As the name suggests, diamonds within the slightly included (SI) grades do have inclusions that are easily seen under 10x magnification. The inclusions may not be large, individually, but they may be enough collectively to affect the performance of the diamond’s brilliance. It is actually quite a big step from SI to I, where inclusions will almost always be visible.

The reason why SI diamonds remain popular is that a diamond which barely fails to make the Very Slightly Included (VS) grade may still look eye-clean. When it comes down to it, nobody outside the jewelry and diamond trade is going to be looking at your diamond ring. This makes eye-clean diamonds a good option for those on a budget.

It is important to note that the spectrum of “Slightly Included” is very large. You can send a diamond to different appraisers and you won’t always get the same answer.

What does SI3 Mean?

Example of an SI3 Clarity Diamond
Example of an SI3 Clarity Diamond (or I1 Clarity Diamond)

Officially, an SI3 grade is given when the clarity of a diamond is not low enough to qualify as Included, in the opinion of the jeweler. This approach helps to sell diamonds that might otherwise appear unattractive due to having an I clarity grade.

Because neither GIA nor almost all other diamond report providers use the SI3 grade, it’s difficult to outline exactly what level of inclusions it applies to. Given that it fills the gap between SI2 and I1, we have to assume that inclusions will be present, but that their visibility is in doubt. GIA separate SI and I grades by the terms “noticeable” and “obvious”. In SI1 and SI2 diamonds, inclusions are noticeable under 10x magnification. In I 1, I2 and I3, they are obvious and may affect both transparency and brilliance.

SI3 Clarity Round Cut Diamond
Another example of an SI3 Clarity

So by applying a little, very unscientific logic, we can probably reach the conclusion that SI3 inclusions are obvious but DON’T affect either transparency or brilliance or both. Indeed, the SI3 grade originally appeared to promote the best I1, eye clean diamonds to a saleable level. I clarity diamonds carry something of a stigma, to the point where many jewelers won’t even stock them. By creating SI3, this got around that particular problem.

Keep reading to learn the massive problem with SI3.

The Problem with the SI3 Diamond

SI2 Clarity Diamond vs SI3 Clarity Diamond
SI2 vs SI3. The SI3 is on the left. The SI2 is on the right

The biggest problem with the SI3 diamond is that very few people seem to accept this grading. This means, that for all practical purposes, the SI3 diamond is actually an I1 diamond.

Buying an SI3 listed diamond may be less expensive than diamonds even just at SI1 or SI2 grades. The problem will come when you have it valued for insurance purposes, or come to sell it. It will, at that point, probably become an I1 grade, if you’re lucky.

The only grading system which uses the SI3 grade is the EGL. EGL is one of the largest issuers of diamond grading reports, especially in Europe. However, they have a slightly patchy reputation when it comes to the clarity grades they issue. As a result, their reports are not as highly regarded as either GIA or AGS. Some specialist jewelry insurers in the US will not accept an EGL report for valuation purposes of very high-ticket items. It will then cost you more money to obtain a GIA or AGS report.

The Pros of SI3 Diamonds

The SI3’s only advantage is that they sound better than I1 clarity. Other than that, there is nothing really going for them…

That’s it.

A Final Word on SI3 Diamonds

Diamond set in bezel engagement ring

You will see them advertised at very attractive prices. Some will have reports, many won’t. The reason they won’t is that jewelers know they can only get them from EGL, so they don’t bother and just apply the grade themselves. Reputable dealers, really, will rarely do this, we should add.

If you want to buy an SI3 diamond, that’s your choice. For all the reasons we’ve given here, though, we strongly recommend avoiding an SI3 diamond. You may buy cheaply, but that’s only because you’re buying a cheap diamond in every sense.

If you find an SI3 diamond that you want, send off to be certified. If it comes back as SI2 or better, grab it. If it’s an I1, you know where you stand.

SI3 Clarity Podcast

Here’s a podcast of Ay and Ben’s opinions on SI3 clarity diamonds.