Clarity Grading For Type 3 Gemstones
The Gemological Institute of America (GIA) system for grading clarity in colored stones divides gem varieties into three types, depending on how included a type of gem tends to be. The best Type 1 gems are very clear, almost completely free of visible inclusions even under 10x magnification. The best Type 2 stones tend to have inclusions that can only be seen under 10x magnification, and even the best Type 3 gems usually have inclusions that can be seen without any magnification at all.
The result of this classification system is that the GIA grading system is a sliding scale, VVS (Very Very Slightly included) is the best grade for all colored gems, even though a Type 3 VVS gem would barely rate as SI2 on the Type 1 scale. It also means that while one can compare the clarity of one emerald to another, it is meaningless to try to compare an emerald's clarity to that of a tanzanite.
The GIA system is far from perfect, can be somewhat confusing, and can be very subjective, but it is sponsored by a leading authority on gemstone quality and is in wide use. On the principle that any standard is better than none, and acknowledging that most people have at least heard of the GIA scale, the gems sold by Gems Evermore are graded using the GIA system.
In an attempt to avoid unnecessary confusion, this page presents only the part of the GIA clarity grading system that applies to Type 3 gemstones. A list of the Type 3 gemstones, and the standards used to grade them, are given in the tables below.
The result of this classification system is that the GIA grading system is a sliding scale, VVS (Very Very Slightly included) is the best grade for all colored gems, even though a Type 3 VVS gem would barely rate as SI2 on the Type 1 scale. It also means that while one can compare the clarity of one emerald to another, it is meaningless to try to compare an emerald's clarity to that of a tanzanite.
The GIA system is far from perfect, can be somewhat confusing, and can be very subjective, but it is sponsored by a leading authority on gemstone quality and is in wide use. On the principle that any standard is better than none, and acknowledging that most people have at least heard of the GIA scale, the gems sold by Gems Evermore are graded using the GIA system.
In an attempt to avoid unnecessary confusion, this page presents only the part of the GIA clarity grading system that applies to Type 3 gemstones. A list of the Type 3 gemstones, and the standards used to grade them, are given in the tables below.
| Family | Variety |
|---|---|
| Beryl |
Bixbite Emerald |
| Tourmaline |
Red Pink Watermelon (green transitioning to pink or red) |
| Grade | Standard | What You See |
|---|---|---|
| VVS | Very, Very Slightly included - Inclusions are easily seen under 10X magnification, but usually not visible to the unaided eye. | The gem is almost perfectly transparent. If you examine the stone closely enough, you may see very tiny flaws. |
| VS | Very Slightly included - Obvious inclusions are easily seen under 10x magnification, and usually visible to the unaided eye. | The gem is still transparent and lively. On close examination, a few small flaws can be seen. |
| SI1 | Slightly Included 1 - Inclusions are large and numerous under 10x magnification, and prominent to the unaided eye. | The gem is mostly transparent, but one or more flaws are easily visible. |
| SI2 | Slightly Included 2 - Inclusions are large and numerous under 10x magnification, and very prominent to the unaided eye. | The gem is generally transparent, but has a number of large flaws. |
| I1 | Included 1 - Inclusions are very obvious and have a moderate negative effect on the appearance OR durability of the stone. | The stone either has so many inclusions that it is only partly transparent, or if transparent it has one or more cracks that might weaken the gem. |
| I2 | Included 2 - Inclusions are very obvious and have a severe negative effect on the appearance OR durability of the stone. | The stone either has so many inclusions that it appears to be translucent, or if transparent it has cracks that could weaken the gem. |
| I3 | Included 3 - Inclusions are very obvious and have a severe negative effect on BOTH the appearance AND durability of the stone. | The stone has so many inclusions that it appears to be translucent, AND it has one or more cracks that weaken the gem. |
