Below are the definitions we use to describe gem clarity. Note that certain gems (such as aquamarine) typically occur in high clarity, while others (such as emerald and rubellite) naturally are found with lower clarities.

Degree of transparency

Transparent (TP). Transparent gems allow light to pass through them without distortion. In transparent gems, one can generally see clearly the back of the stone when looking through the top. Examples include most faceted gems, such as amethyst, sapphire, etc.

Translucent (TL). Translucent gems allow light to pass through them, but the light is distorted to such a degee that one cannot clearly see the back of the stone. Examples include jade and agate.

Opaque (O). Opaque gems allow no light to pass through them, even at the thin edges. Examples are turquoise and hematite.

Clarity grades

Eye Clean (EC). No inclusions visible to the naked eye from any angle.

Examples of Eye Clean (EC) gems

Very Slightly Included (VS). These gems are transparent and have excellent brilliance. They might have some minor inclusions, common to that particular gem type, but these do not deter from the rarity and beauty of the gem. VS gems show very slight inclusions visible to the naked eye.

Examples of Very Slightly Included (VS) gems

Slightly Included (SI). These gems have some inclusions visible to the naked eye, but not to the extent of significantly affecting the brilliance of the gem.

Examples of Slightly Included (SI) gems

 

Moderately Included (MI). These gems have some larger and/or many minor inclusions that somewhat diminish brilliance.

Examples of Moderately Included (MI) gems

 

Included (I). These gems have some larger and/or many minor inclusions that significantly diminish brilliance.

Examples of Included (I) gems