Diamond Clarity Grades
To understand what SI3 clarity is, let’s take a look at the grading scale used to evaluate diamond clarity. One of the most widely used scales is that devised by the G.I.A. (Gemological Institute of America), which uses six main grades (from highest to lowest): FL, IF, VVS, VS, SI and I.
The highest clarity grade is FL, which stands for Flawless – these diamonds don’t have flaws that can be viewed under 10x magnification.
The next best thing are the stones graded IF (Internally Flawless), which have only insignificant surface blemishes.
Then you have the VVS (Very Very Slightly Included) grade, followed by VS (Very Slightly Included).
SI, or Slightly Included, is the next grade, and the lowest clarity you can get is I, standing for Included.
What Is SI3 Clarity?
SI3 clarity is advertised as a subdivision of the SI clarity range.
Diamonds graded SI have inclusions that are easy to see under magnification but may not be visible to the naked eye.
The G.I.A. clarity scale described above divides the SI grade into SI1 and SI2; on this scale, the next grade after SI2 is I1, which is the top clarity in the I (Included) range.
SI3 clarity doesn’t exist on the G.I.A. scale; it is used by the E.G.L. (European Gemological Laboratory) and is part of its grading system.
However, there are jewelers who use the term SI3 simply to refer to diamonds that cannot be graded SI2 but do not have as many visible flaws as the stones graded I.
Why Is SI3 Clarity Controversial?
SI3 clarity is subject to a lot of debate because most major grading scales do not use this designation.
According to the E.G.L. scale, SI3 diamonds are stones that would be graded either SI2 or I1 on the G.I.A. scale, i.e. diamonds on the margin between the SI and I ranges.
However, since many people only think of the G.I.A. scale when judging clarity, they are unaware that a diamond advertised as SI3 could be graded as I1 by the G.I.A. Instead, they may be led to believe that a diamond with clarity I is in fact an SI stone.
Why is all that a problem?
The main issue is that a diamond graded SI may or may not have inclusions visible to the naked eye. However, a diamond graded I will usually have flaws that are readily visible.
Because of that, there is a significant drop in price for diamonds that fall in the I category. And needless to say, you wouldn’t want to buy a stone with visible inclusions at the price of an SI diamond.
Is SI3 Clarity a Scam?
Technically speaking, SI3 clarity exists, and if you are looking at a grading report issued by the E.G.L., it may be there.
However, although the very existence of the official SI3 grade is not a scam, it can be used by less than scrupulous sellers to mislead you that a diamond they call SI3 is definitely an SI diamond on the G.I.A. scale.
You should remember that someone selling a diamond that would be graded SI2 by the G.I.A. doesn’t have the incentive to tell you that the stone is SI3, which sounds worse (unless the stone has been graded by the E.G.L. itself).
On the other hand, there are sellers who carry stones that would be considered I1 on the G.I.A. scale, and they could advertise them as SI3 to make the offer sound better and charge you a higher price.
Often, these diamonds don’t have an official grading report issued by a reputable laboratory, and you shouldn’t pay for them as much as you would for an SI diamond certified by the G.I.A.
How Not to Be Deceived When Buying Diamonds
Sometimes, SI3 diamonds will be sold with a certificate that lists this grade.
You should remember, however, that just because a diamond has a certificate, it doesn’t mean that you can fully trust it. It is much more important who issued it, and if that’s not a renowned authority such as the G.I.A., you should be careful.
There are many small labs that grade diamonds, and you don’t always know what their grading standards are and whether they are truly independent from the seller.
So, if in doubt, don’t buy an SI-clarity diamond that doesn’t have a grading report issued by the G.I.A.
Very often, diamonds sold as SI3 will have some inclusions visible with the naked eye, and for this reason, they would not be able to be graded SI2 (the G.I.A. would grade them I1).
However, if the diamond is mounted, the setting may conceal such flaws, making the diamond look fine, and you may be led to believe that it is really an SI-clarity stone.
That’s why you should buy diamonds loose and examine them from all sides under magnification.
If you spot any flaws visible to the naked eye on the side of the diamond, you should not be paying a price higher than what I1 diamonds sell for.
In sum, if someone tries to sell you and SI3 diamond, always keep in mind that it may be just an I1-clarity stone, and be cautious.