What are SI Diamonds? Is there a Difference Between SI1 and SI2 Diamonds?

What are SI Diamonds

When making a decision on the type of diamond you want to buy for a specific occasion, one factor you have to take really serious asides color, cut, and carat weight is clarity. Talking about clarity, we are going to be looking at two distinct diamonds which are the SI1 and SI2. This comparison features these two adjacent diamond clarity grades, which are often compared by many people looking to purchase their diamonds.

Taking a look at the grading scale used by the Gemological Institution of America, the representation of diamond clarity grades makes use of letters. Talking about the SI clarity grade, we are talking about the fifth-best grade on this scale.

The other grades higher than the SI grade are as follows:

  • The FL grade (the flawless grade)
  • The IF grade (internally flawless)
  • The VVS grade (very, very, slightly included)
  • The VS grade (very slightly included)

The SI diamond clarity grade is much more intense than the other grades as it is further split into two sub-grades which are:

  • SI1 (slightly included 1)
  • SI2 (slightly included 2)

A deeper look at the SI1 and SI2 diamonds

Looking at the SI1 Clarity diamonds, there are inclusions that can be spotted, not easy with the naked eyes but with magnification lens from 10X or higher. In some special cases, these flaws can be seen with the naked eyes, but most of the time, barely noticeable.

Now talking about SI2 clarity diamonds, these inclusions are visible under a simple microscope or even the naked eye.

GIA Certified 1.04 Carat Cushion CutShape 14K White Gold Classic Prong Set Diamond Engagement Ring 4 Prong with a 0.53 Carat, J Color, SI1 Clarity Center Stone
GIA Certified 1.04 Carat Cushion Cut/Shape 14K White Gold Classic Prong Set Diamond Engagement Ring 4 Prong with a 0.53 Carat, J Color, SI1 Clarity Center Stone

Differences Between the clarity in SI1 and SI2 Diamonds

The major difference between the clarity in SI1and SI2 diamonds lies in how visible the inclusion is to the eye. Inclusions in SI2 diamond stones are much more noticeable than those in SI1 stones. This higher visibility is based on the fact that there are bigger and more numerous intrusions in the SI1 diamond.

The SI2 diamonds inclusions are visible under magnification glasses and sometimes under the naked eyes. Looking at the intrusions in the SI2 diamonds, it is more likely that you find them close to the lower edge of the diamond, which means that it looks clean when looked at from the top of the diamond. It is still possible that you see these flaws from the side of the diamond as well, even without the use of a magnifier.

It is therefore advised that when you want to purchase a diamond, try getting one from somewhere; you are allowed to not only get close to the stone but also view it from all angles.

The Choice Between SI1 and SI2 Diamonds

From the information provided so far, the obvious choice might be to buy the SI1 diamonds without a doubt as they are cleaner than the SI2 diamonds, but sometimes the choice of what to buy might fall between the balance of the price as well as the quality. This is true because not all diamonds are the same, and not all the factors which we have highlighted happen to all the diamonds in question.

At a point, you might get to notice an SI2 diamond with fewer inclusions than another SI1 diamond. This points to the fact that your choice should sometimes fall in the bracket of clarity levels as well as the diamonds that look great to you. So, whether SI1 or SI2, your first priority should be finding diamonds that are clean without intrusions visible to the eye. Most of the time, when looking to purchase a stone, you would find these diamonds categorized, which means that you would have to select based on the classification.

Yes, this might be the outright choice but not the best criterion for making the best choice. Sometimes, you might find an SI2 diamond stone better than any SI1 you have ever seen before.

What are SI Diamonds
VIP Jewelry Art 1.50 CT TW GIA Certified Brilliant Cut Large Diamonds Engagement Ring in 14k White Gold

Bottom Line

We have covered the basics of these diamond stones and what they look like talking about and how to visible tell the difference even if they are not categorized. The understanding of the similarities, as well as the differences, would help you make good decisions on the best diamond to purchase. Over time, there have been many distinct differences between the SI1 and SI2 diamonds, but at the same time, there have been many similarities.

Most of the time, without the right information, you might most likely not be able to tell the difference because of the angle of viewing intrusions. Finally, it all boils down to personal choice and the patience to actually get something nice within the range of what you are looking to purchase. Do take out time to get the best based on what you have found out today, and believe me; you would be happy you did.

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Carl Jones

Carl has been involved in the jewelry business since his youth. Growing up in South Africa his parents were jewelers who worked in the industry for decades.

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