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

Grading diamonds are both objective and subjective. 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.

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.

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 the reduced light reflection.

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

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.

What does SI3 Mean?

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

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.

The Cons of SI3 Diamonds

SI2 Clarity Diamond vs SI3 Clarity Diamond

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

Buying an SI3 listed diamond will undoubtedly 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 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

They’re cheap. They sound better than I1 clarity.

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 you to avoid such diamonds. 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.