GIA Type I Clarity Chart       

VVS   Very Very Slightly Included - Minute to not detectable
VS    Very Slightly Included -         Minor inclusions

SI1   Slightly Included -                NOTICEABLE to obvious
SI2   Slightly Included 2 -             OBVIOUS to noticeable
I1    Included 1 - Prominent -      moderate effect on appearance or durability.
I2    Included 2 - Prominent -      severe effect on appearance & durability.
I3    Included 3 - Prominent-     severe effect on beauty, transparency & durability

Type 1 Gemstones are gems that are normally found to be clean.  
This includes gems such as:
Aquamarine, Amethyst, Citrine, Danburite, Topaz(Blue), Kunzite, Tanzanite, Beryl(Pink, Green,and Yellow) , Morganite , Spodumene, Tourmaline(Green), Yellow Chrysoberyl, Zircon(Blue and Clear), Zoisite.

GIA Type II Clarity Chart      

VVS   Very Very Slightly Included - Minor inclusions
VS    Very Slightly Included -         NOTICEABLE to Obvious
SI1   Slightly Included -                Noticeable to OBVIOUS
SI2   Slightly Included 2 -              Obvious to Prominate                 

I1    Included 1 - Prominent -      moderate effect on appearance or durability.
I2    Included 2 - Prominent -      severe effect on appearance &     durability.
I3    Included 3 - Prominent-  severe effect on beauty, transparency & durability.

Type 2 Colored Gemstones by their nature have natural inclusions. 
(Inclusions are the norm) This includes gems such as:
Ametrine, Amblygonite, Andulusite, Apatite. Alexandrite, Crysoberyl, Diopside, Feldspar, Flourite, Garnet(All species), Iolite, Natrolite, Fire Opals, Phenakite, Peridot, Quartz, Rhodolite, Ruby, Scapolite, Spinel, Sapphire, Taaffeite, Topaz(all colors EXCEPT Blue), Tourmaline( All colors EXCEPT Green and watermelon), Tzavorite, Zircon(All colors EXCEPT Blue and Clear).

GIA Type III Clarity Chart      

VVS   Very Very Slightly Included - NOTICEABLE to obvious
VS    Very Slightly Included -         Noticeable to OBVIOUS 
SI1   Slightly Included -                Obvious to prominent
SI2   Slightly Included 2 -             Obvious to PROMINENT
I1    Included 1 - Prominent -   considerable effect on appearance   or durability
I2    Included 2 - Prominent -   severe effect on transparency or durability
I3    Included 3 - Prominent -   severe effect on beauty, transparency & durability

Declasse -                   Stones not transparent because of inclusions. 

Type 3 Colored Gemstones by their nature have many natural inclusions.
(Heavily Included is the norm) This includes gems such as:
Benitoite, Emerald, Idocrase, Kyanite, Prehnite, Red Beryl, Rhodochrosite, Red Tourmaline, Sphalerite, Sphene, Watermelon Tourmaline.