Colored Stone Grading System


I use and recommend my own colored stone grading system. “Common Sense Gemstone Grading” by Jeff R. Graham copyright 2007.

This is the Gem Institute of America’s colored stone grading system. I have been told by GIA gemologists that this system is still being modified and worked on by them. So be aware there may be changes.

May 2008 – GIA is still using this basic system but they have made modifications to it. I was recently contacted by a GIA Senior Instructor and told this. When I asked for a link to or a copy of the updated grading system (so I could update this article). I got the typical GIA answer (which is one of many reasons I do not care for the GIA). You have to buy the books and course work. Trust me nothing GIA sells is cheap. My answer was when pigs fly. So if you want the current GIA system being used you will have to contact GIA and probably pay for it

Note: I would also note that GIA has created a cutting grade for the actual faceting/cutting of the gemstones.

I have listed this system because it is being used by GIA gemologists (of course) and some others in the gemstone industry. If you are buying GIA certified stones, chances are you will encounter this system. Be careful and read the clarity definitions between the three “type categories”, they are different even though the clarity letters are the same (VS, VVS, SI1). Notice that there are different “Types” for the same families of gemstones. For Example, Tourmaline is in several “Types”.

Note: That the GIA system does not have an “IF” clarity grade for colored gemstones.

I personally do not agree with this and think there should be an “IF” grade. In my opinion this smells like politics to me. I have been quite vocal about it to several GIA people that I know, we agree to disagree.

I think, by not having an “IF” category they are lowering the grade of all colored gemstones. Their argument/excuse is that by looking in a microscope they can always find a spot, crystal growth, included crystal, or whatever, if they look long enough. This is true of any gemstone if you look long enough and with enough magnification. But the standard has always been (and will be) that if an “expert” cannot see any inclusions/flaws under a 10x power loupe the stones are judged to be “IF” (internally flawless).

My personal opinion is that there are some gemstones that are exceptional and they need to be graded that way. Not lumped in with everything else and graded a lower clarity grade to make the lower clarity material look better. When a stone is exceptional, it should be graded that way.

I do not use this system for grading my colored stones, with the exception of an occasional stone that I have had certified by a GIA gemologist. I do not like GIA’s system and think it’s confusing to customers and frankly in my opinion leaves a lot of loose ends for unethical people to operate in. But this is my personal opinion and this system is being used commercially, so I have posted it for informational purposes.

I think there are a lot of things going on in this grading system that I have not mentioned. Read through it and draw your own conclusions.

Type I – Gemstones

Beryl
Aquamarine
Green
Morganite
Yellow
Chrysoberyl
Green
Yellow
Quartz
Smokey
Spodumene
Kunzite
Green
Topaz
Blue
Yellow
Orange
Pink
Red
Tourmaline
Green
Zircon
Blue
Zoisite
Tanzanite

Type 1 – Clarity

VVS – Very, Very Slightly Included (the best) Minute inclusions that are difficult to see using 10X, and are not visible at all to the naked eye.

VS – Very Slightly Included Minor inclusions that are easier to see using 10X, but still not visible to the naked eye.

SI1 – Slightly Included I The inclusions are easily seen using 10X, and are noticeable with the naked eye.

SI2 – Slightly Included 2 The inclusions are more easily seen using 10X, and are quite visible with the naked eye.

I1 – Included 1 The inclusions are very obvious and they have a moderate negative effect on the over-all appearance or durability of the gemstone.

I2 – Included 2 The inclusions are very obvious and they have a severe negative effect on the over-all appearance or durability of the gemstone.

I3 – Included 3 The inclusions are very obvious and they have a sever negative effect on both the over-all appearance and durability of the gemstone.

Type 2 – Gemstones

Andalusite All
Chrysoberyl
Alexandrite
Corundum
All colors (i.e. Sapphire and Ruby)
Garnet
All species and colors
Iolite – All
Peridot – All
Quartz
Amethyst
Citrine
Ametrine
Spinel – All
Tourmaline
Blue
Orange
Yellow
Multi-colored (except watermelon color)
Zircon
Green
Orange
Red
Yellow

Type 2 – Clarity

VVSVery, Very Slightly Included (the best) Minor inclusions that are somewhat easy to see using 10X, but still not visible to the naked eye.

VS – Very Slightly Included Noticeable inclusions that are easier to see using 10X, and may be slightly visible to the naked eye.

SI1 – Slightly Included I The inclusions are easily seen using 10X and are large or numerous, and are noticeable with the naked eye.

SI2 – Slightly Included 2 The inclusions are easily seen using 10X and are large or numerous, and are very noticeable with the naked eye.

I1 – Included 1 The inclusions are very obvious and they have a moderate negative effect on the over-all appearance or durability of the gemstone.

I2 – Included 2 The inclusions are very obvious and they have a severe negative effect on the over-all appearance or durability of the gemstone.

I3 – Included 3 The inclusions are very obvious and they have a sever negative effect on both the over-all appearance and durability of the gemstone.

Type 3 – Gemstones

Beryl
Emerald
Tourmaline
Red
Pink
Watermelon (green transitioning to pink or red)

Type 3 – Clarity

VVS – Very, Very Slightly Included (the best) Noticeable inclusions that are easy to see using 10X, but usually not visible to the naked eye.

VS – Very Slightly Included Obvious inclusions that are easy to see using 10X, and usually visible to the naked eye.

SI1 – Slightly Included I The inclusions are large and numerous using 10X, and prominent with the naked eye.

SI2 – Slightly Included 2 The inclusions are large and numerous using 10X, and very prominent with the naked eye.

I1 – Included 1 The inclusions are very obvious and they have a moderate negative effect on the over-all appearance or durability of the gemstone.

I2 – Included 2 The inclusions are very obvious and they have a severe negative effect on the over-all appearance or durability of the gemstone.

I3 – Included 3 The inclusions are very obvious and they have a sever negative effect on both the over-all appearance and durability of the gemstone.