The clarity of a diamond is one of the four C's that determine the quality of a diamond. Ideally, a diamond is completely transparent and translucent - in reality, however, the majority of gemstones have imperfections and are more or less heavily clouded. This has the consequence that the much sought-after sparkle is reduced. The features referred to as inclusions can be embedded foreign minerals, tiny cracks or growth-related crystal defects. The rating of the clarity (purity) turns out to be better, the fewer inclusions are present and the smaller and less conspicuous they are placed. It is most unfavorable when the inclusions are in the middle of the table facet - there they are immediately apparent. It is better,

The GIA scale for classifying clarity

The system for grading clarity (purity) developed by the GIA (Gemological Institute of America) is an internationally binding standard. The assessment takes into account the size, type, position, color and number of inclusions.
The clarity scale ranges from the top categories FL (flawless, flawless) and IF (internally flawless, flawless) to VVS1 and VVS2 (very very small inclusions), VS1 and VS2 (very small inclusions, very small Inclusions), SI1 and SI2 (small inclusions) up to I1, I2 and I3 (inclusions), where clear impurities can be seen even with the naked eye.
The majority of diamonds belong to the VS and SI classes; higher quality levels are very rare and accordingly expensive.