SI1 & SI2

SI1

An SI1 diamond is a diamond with a clarity grade that stands for "Slightly Included 1". An SI1 diamond is a diamond with a clarity grade that stands for Inclusions in a VS1 diamond are typically small, and they may include tiny crystals, clouds, or feathers. They are usually not visible to the naked eye and are only visible to a trained gemologist under magnification.

This is VERY difficult to achieve in the SI1 category. An SI1 has a lot more going on in the diamond. It can have multiple imperfections or it can have one giant one. There is so much variation in diamonds that have the SI designation. We would recommend a diamond like this from JAMES ALLEN or this from WHITE FLASH over a diamond like the one we picture below.

Example: Bad SI1

Reason: SI1 example on Table and Reflecting

Example: Bad VS2

Reason: Example of bad VS2 GIA center black

SI2

An SI2 diamond is a diamond with a clarity grade that stands for "Slightly Included 2". This means that the diamond has inclusions or blemishes that are visible under 10x magnification and today are usually visible to the naked eye. 20 years ago, an SI2  provided good value. It still can today, but almost 90% of the SI2 rated diamonds out there have imperfections that will be visible to the naked eye.

They may not be at first glance when the diamond is shiny and new, but as soon as it gets dirty, those inclusions can rear their ugly heads. If you are going to buy an SI2, Do not purchase stones like this or this, but absolutely consider a diamond like this.

Example: Bad SI2

Reason: SI2 example on Table and Reflecting

Example: Good SI1

Example: Bad SI2

Reason: SI2 example on Table and Reflecting

Example: Good SI2

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