The Controversy Regarding the SI3 Grade of Diamonds

Below is a detailed explanation of the same.

Diamond Clarity Grades

The commonly used scale determined by the Gemological Institute of America has six grades. The FL stands for Flawless and represents the highest quality of diamonds. The IF follows this, which stands for Internally Flawless diamonds that have only a few surface blemishes on them. The next is the VVS or Very Very Slightly Included clarity grade, which is followed by the SI or Slightly Included.

The GIA scale divides the Slightly Included diamonds further into SI1 and SI2. The truth is, SI3 grade does not exist in the GIA clarity scale but is employed by the European Gemological Laboratory to grade gemstones of low clarity.

The general confusion regarding SI3 was because it was being advertised as a subcategory under the SI range. In fact, many jewelers use the term SI3 to define a 7 ct diamond ring that cannot be included in SI1 but does not have the number of visible flaws as SI2 grade either. However, as the GIA does not grade such stones, they will be of very value in the US.