SI (Slightly Included): Diamonds with SI clarity have inclusions visible under a 10x magnifier. While these imperfections can be seen, they don’t greatly impact the diamond’s overall appearance to the naked eye.

VS (Very Slightly Included): VS diamonds have inclusions that are very difficult to see even with a 10x magnifier. The imperfections are minor and generally don’t affect the diamond's beauty, making them a popular choice for their value.

VVS (Very Very Slightly Included): VVS diamonds have extremely tiny inclusions that are nearly impossible to detect with a 10x magnifier. These diamonds have very high clarity and are often quite expensive due to their near-perfect visual quality.