The Full Story
The SI3 Diamond Clarity Grade
GIA considered using the SI3 Diamond Clarity Grade at one point, but decided against it.
EGL Reports, along with The Rapaport Diamond Price Sheet contain the SI3 grade.
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Clarity factors are very important when determining a clarity grade for a diamond. However, the clarity factors can certainly be subjective; two factors in particular. Those two factors are size and number of inclusions.
GIA Diamond Clarity Grades are gathered using words like, "easy," "noticeable," "somewhat," and "quite." These words provoke different opinions in others.​​
Here is an accurate example of EGL using the SI3 grade in the market.
Consider the Five Clarity Factors
1) Inclusion Size: noticeable (SI category size) (POSITIVE)
2) Number of Inclusions: reflective/ many (NEGATIVE)
3) Location of Inclusions: Under the Table (NEGATIVE)
4) Inclusion Contrast (Relief): Black Inclusions (NEGATIVE)
5) Nature of Inclusions: no severe impact (POSITIVE)
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Judging as to whether this is an SI2 or I1, you can see the negative outweighs the positive. Therefore this diamond would certainly be an I1, not an SI2, by GIA standards.​​​
However, considering the SI3 Grade on this stone, if you were to view this diamond with your naked eye and no magnification, the reflective black inclusions are not sprinkled everywhere, darkening the diamond.
Instead, these inclusions fall within the diamonds cut pattern. GIA states, "a stone with an eye-visible inclusion can be graded SI" and "You'll usually see eye-visible inclusions more often in an SI2 stone" than an SI1 (pg 119).
The Black Cystals in this stone disguise themselves within the diamond's cut pattern and are not neccessary obvious unless you are nearsighted. That is an SI3.
Since the Rapaport New York Diamond Price Sheet hit the market in 1978, EGL and diamond manufacturers have no problem placing diamonds into this category for pricing as a prized I1.
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The downside to this grade is that it is not mandated by GIA. Therefore the market abuses it when they can.​​​
EGL HONG KONG no. 1700143824
https://www.eglhk.com.hk/verification/result.php?reportno=1700143824&weight=
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ADDRESS FOR LISTED DIAMOND
In order to even better understand the SI3 Grade, it is a must to accurately know GIA's method for clarity grading SI2 and I1 Diamonds.
The GIA course material for Diamond Clarity (pages 15-16/ GIA digital literature) states:
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SI2 by GIA Definition:
"SI stones contain noticeable inclusions that are easy (SI1) or very easy (SI2) for a trained grader to see under 10X magnification. Typical inclusions are included crystals, clouds, and feathers. These inclusions are usually centrally located. A stone with an eye-visible inclusion can be graded SI; you’ll see eye-visible inclusions more often in an SI2 stone."
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I1 by GIA Definition:
"Diamonds that fall in the Included (I) range contain inclusions that are obvious to a trained grader under 10X magnification. They can be seen face-up without magnification. The inclusions in I1 diamonds are usually quite visible to the unaided eye.
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You'll notice when defining the SI2 grade, GIA first states, "very easy for a trained grader to see under 10X magnification." Yet, following this, they then state, "you'll see eye-visible inclusions more often in an SI2 stone."
Now, looking at the I1 grade, GIA again states, inclusions "can be seen face-up without magnification" and
"are obvious to a trained grader under 10X magnification." This also means "eye-visible" (without magnification.)​
Therefore, not only do we see both grades containing similar definitions by GIA, but we also rely on the opinions of what some people can see and others cannot. Opinions are not facts. ​ Said before, the market tends to use the SI3 Grade for over-grading diamonds; given it is not in GIA's Diamond Grading System. The diamond above was not over-graded.​
Consider the Five Clarity Factors
1) Inclusion Size: visible black clouds/ not SI (NEGATIVE)
2) Number of Inclusions: Throughout Diamond (NEGATIVE)
3) Location of Inclusions: Throughout Diamond (NEGATIVE)
4) Inclusion Contrast (Relief): Black Clouds (NEGATIVE)
5) Nature of Inclusions: no severe impact (POSITIVE)
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There is no question. This would not qualify as an SI3. ​​The extremely black clouds place it at the very best in the I1 category.
Here are two examples shown below of over-graded SI3 diamonds.
DIAMOND ONE:
They darken the diamond. This is an I2 by GIA Standards. These Black Clouds are easily visible with the naked eye.
​​Sadly, this is an example of the SI3 grade being abused in the diamond market. See the report below.
EGL HONG KONG no. 1700221518
https://www.eglhk.com.hk/verification/result.php?reportno=1700221518&weight=
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ADDRESS FOR LISTED DIAMOND
DIAMOND TWO:
Consider the Five Clarity Factors
1) Inclusion Size: Large, easily (NEGATIVE) not SI size
2) Number of Inclusions: Many (NEGATIVE)
3) Location of Inclusions: Throughout (NEGATIVE)
4) Inclusion Contrast (Relief): White & Colorless (NEUTRAL)
5) Nature of Inclusions: Severe Knots- Fractures (NEGATIVE)
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​If you were to question as to whether or not this is an SI3,
you can see 4 out of 5 factors were negative and nothing was positive in relationship to the SI category.
Therefore it would fall in the "I" Included category.
Unfortunately, this is possibly an I3 Diamond Clarity Grade by GIA standards if submitted; given the encompassing cloud and fracture running across the diameter of the diamond that can allow it to break or cleave if dropped.
This diamond does not have a Commercial Laboratory Report
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ADDRESS FOR LISTED DIAMOND:
Let's also be clear that a lot of people frown upon the SI3 grade because it was merely added to GIA's Grading System by an individual (Tom Tashey). Yet, GIA decided against using it.
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EGL and other commercial laboratories still use the grade today (2024.) Yet again, they are using the Diamond Clarity Grading System developed by GIA; adding their own grade or category to it. Because of the controversy, manufacturers and sellers tend to call obvious I1 diamonds, SI3. As you can see above, sometimes the grade can be worse than an I1.​
Remember, the market, not GIA, gives validity to the SI3 grade. It is used on the New York Rapaport Price sheet (see the index.) This price sheet is used globally by diamond brokers and manufacturers. ​ Interesting enough, in fine print on this price sheet in reads:
​Rapaport Price Sheet category example with the SI3 Diamond Grade
​"Prices in this report reflect our opinion of NEW YORK HIGH CASH ASKING PRICES. These prices are often discounted and may be substantially higher than actual transaction prices. No guarantees are made and no liabilities are assumed as to the accuracy or validity of this information © by Rapaport USA Inc. All rights reserved. Reproduction in any form is strictly prohibited."
​The SI3 grade is not used in the GemGuide. The Guide, by Gemworld International, is only associated with the GIA Grading System. Gemworld International provides true market research pricing on all gems, all over the world; not just diamonds within the New York Diamond District.
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In conclusion, there is nothing wrong with the SI3 grade if used properly in my opinion. However, according to GIA it would be a top I1 diamond if graded.
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Let me add, this is not a grade that I would use because it is not part of the GIA Diamond Grading System.
​The reports and sellers shown are publicly assessable. You can find them on the URLs below the Lab Report.