GIA Type & Clarity Classifications
The GIA (Gemmological Institute of America) classifies gems into three types based on the prevalence of inclusions. These and their corresponding GIA coloured gemstone clarity grades are detailed below.
| Type Classification | Severely Included | Heavily Included | Moderately Included | Slightly Included | Eye-Clean |
|---|---|---|---|---|---|
| Type I These gems grow extremely clean in nature and usually have no eye-visible inclusions, for example Aquamarine | Prominent inclusions severely affect appearance, durability, or both. | Prominent inclusions negatively affect appearance, durability, or both. | Moderate inclusions somewhat easy to see with the unaided eye. | Minute inclusions difficult to see with the unaided eye. | The gemstoneappears clean to the unaided eye. No visible inclusions when the gemstone is examined six inches from the naked eye. |
| Type II These gems typically grow with some minor inclusions in nature that may be eye-visible, for example Ruby. | Prominent inclusions severely affect appearance, durability, or both. | Prominent inclusions negatively affect appearance, durability, or both. | Noticeable inclusions apparent to theunaided eye. | Minor inclusions somewhat easy to see with the unaided eye. | The gemstoneappears clean to the unaided eye. No visible inclusions when the gemstone is examined six inches from the naked eye. |
| Type III These gems typically grow with many inclusions in nature and they are usually eye-visible, for example Emerald. | Prominent inclusions severely affect appearance, durability, or both. | Prominent inclusions negatively affect appearance, durability, or both. | Obvious inclusions very apparent to the unaided eye. | Noticeable inclusions apparent to theunaided eye. | The gemstoneappears clean to the unaided eye. No visible inclusions when the gemstone is examined six inches from the naked eye. |
Modified table from The Gem Guide, GemWorld International, Inc.