SI2 vs I1 Diamonds Clarity – What is The Actual Difference?

Last Updated on September 1, 2022

Diamond clarity is one of the most important factors when it comes to selecting a diamond.

Clarity refers to the way light refracts through a diamond and is responsible for producing the signature sparkle of a diamond.

However, not all diamonds have the same clarity.

SI2 and I1 diamonds are two clarity grades that have a few fundamental differences to consider before making the choice to purchase.

Here’s a look at the differences between an SI2 and I1 diamond to help you choose which grade of diamond is right for you.


What Are SI2 Diamonds?

SI2 (slightly included) diamonds are diamonds that have multiple inclusions that may be visible to the naked eye and can impact the performance of the diamond.

SI2 diamonds are between SI1 and I1 diamonds on the Gemological Institute of America (GIA) clarity scale and may have a variety of inclusions, including:

  • Dark spots
  • Twinning wisps
  • Etch channels

Inclusions on SI2 diamonds may be large or dark and can impact the brilliance and durability of a diamond.

However, because inclusions on SI2 diamonds are visible from a profile view and not top-down, some ring settings may be able to hide inclusions effectively.

What Are I1 Diamonds?

I1 (included) diamonds are diamonds that have several significant inclusions spread throughout the diamond.

I1 diamonds are the highest grade within the included category of diamond clarity.

Inclusions on I1 diamonds are typically large, dark, and visible to the naked eye.

Additionally, inclusions on I1 diamonds are so numerous that they impact the overall structural performance of the diamond and impact light performance and durability.

There are no specific types of inclusions unique to I1 diamonds. Inclusions may include:

  • Cavities
  • Pinpoint
  • Etch channel
  • White feathers

Because of the large number of inclusions, an I1 diamond will be susceptible to damage, such are cracking, chipping, and shattering if dropped – especially if the inclusion is located on a delicate area, such as a thin girdle.

Inclusions on I1 diamonds are relatively difficult to hide with a ring setting because they are so widespread.

Differences Between SI2 and I1 Diamonds

While SI2 and I1 diamonds may appear similar, there are a few fundamental differences between the two, including:

Impact of Inclusions

While both SI2 and I1 diamonds have many inclusions, I1 diamonds have inclusions that are more severe than SI2 diamonds.

These inclusions may include a colored twinning wisp that reduces the brilliance and overall appearance of the diamond or a deep cavity that increases the risk of chipping or cracking if dropped.

Although the two grades of diamonds may appear similar, I1 diamonds will have larger, darker, and more severe inclusions than SI2 diamonds.


While I1 diamonds are rarely ever eye-clean, it is possible to find SI2 diamonds that don’t have inclusions visible to the naked eye.

SI2 diamonds that are one carat or less typically produce a flawless appearance because of the small size of the inclusions.

This can be an incredible savings opportunity since diamonds with higher clarity grades fetch premium prices.

However, it’s recommended to always view SI2 diamonds under high resolution to ensure it’s truly eye-clean.


Another difference between SI2 and I1 diamonds is the price.

As a general rule, the fewer inclusions within a diamond, the higher the price.

Because I1 diamonds have a large number of inclusions, they are less expensive than higher clarity grade diamonds.

Compared to an SI2 diamond, an I1 diamond will be on average 18% less expensive.


Durability is an important factor when selecting a diamond because it impacts the physical structure of the diamond.

SI2 diamonds are more durable than I1 diamonds because they have fewer and less impactful inclusions.

Because I1 diamonds have more inclusions, their durability is reduced and puts them at increased risk of chipping or cracking if dropped.

It’s recommended to pair an I1 diamond with a strong ring setting, such as a bezel setting, to improve durability and reduce the risk of damage.

Center Stone

When choosing a center stone for an engagement ring, it’s recommended to start with a diamond with a grade of at least SI2.

SI2 diamonds will produce more brilliance than I1 diamonds and will most likely appear eye-clean.

I1 diamonds are not recommended for center stones due to the large number of noticeable inclusions that will impact the brilliance and appearance of the diamond.

However, I1 diamonds may be a good option for accent stones to enhance the overall brilliance of an engagement ring.

Eran Hayo is the Chief Editor of Jewels Advisor, with over 5 years of experience in the fields of jewelry and memorabilia. He built Jewels Advisor to serve one main purpose – to teach you everything he knows about jewelry, and help you make better-informed decisions when buying diamonds and engagement rings online. His work has been cited on famous publications such as The Sun, MSN and WikiHow.