A Guide to Diamond Clarity and the Diamond Clarity Chart

The journey of a diamond begins with carbon atoms hidden far below the earth's surface. Subjected to immense heat and pressure, they remain deep within the earth’s mantle until volcanic eruptions bring them to the surface via rare geological formations called kimberlite pipes.

This process can result in various internal characteristics called ‘inclusions’ and external characteristics called ‘blemishes’, which can disrupt the path of light through a diamond, thereby diminishing its brilliance. Clarity measures the number, size, position and color of these inclusions and blemishes, with the diamond clarity grading scale forming a core part of the 4Cs of diamond quality – cut, color, clarity and carat weight. 

What is a diamond clarity chart? 

A diamond clarity chart is a visual representation or scale used to assess and communicate the clarity characteristics of a diamond. Clarity refers to the presence of any internal inclusions or external blemishes; if present, these imperfections can affect a diamond's overall appearance. One of the most widely used diamond clarity charts was developed by the Gemological Institute of America (GIA). 

Established in 1931, the GIA is a public-benefit, non-profit institute renowned for its gemological research. The GIA protects consumers through analysis, education, and gem grading and sets global quality standards. The GIA independently verifies the origins of many of Graff’s diamonds and gemstones. 

The GIA diamond clarity chart

The GIA diamond clarity chart has six categories, some of which are sub-divided, resulting in a total of 11 grades: 

Flawless (FL): No inclusions and no blemishes visible under 10 times magnification. These diamonds are extremely rare and represent the pinnacle of diamond clarity. 

Internally Flawless (IF): No inclusions visible under 10 times magnification.

Very, Very Slightly Included (VVS1 and VVS2): Inclusions so slight they are difficult for a skilled grader to see under 10 times magnification.

Very Slightly Included (VS1 and VS2): Inclusions are observed with effort under 10 times magnification but can be characterized as minor.

Slightly Included (SI1 and SI2): Inclusions are noticeable under 10 times magnification.

Included (I1, I2, and I3): Inclusions are noticeable under 10 times magnification, which may affect transparency and brilliance.

To the naked eye, a VS1 and an SI2 diamond may look the same, but these diamonds are quite different in terms of their overall quality. This is why an expert and accurate assessment – and an understanding of diamond clarity and the diamond clarity chart – is crucial.