Description of Gemological Institute of America Clarity
Grades & Types
Colored stones are graded with respect to their clarity
being relative to their mode of formation. As with diamonds, 10x magnification is used.
Final assessment is with the unaided eye.
Type 1 Stones -
Stones which are fashioned from rough which is plentiful in an inclusion-free
state.
Included in this class are:
Beryl - Aquamarine,
Goshenite, Morganite, Heliodor
Quartz - Citrine and Smoky
Spodumene - Kunzite
Topaz
Tourmaline (green)
Zircon (blue)
Zoisite - Tanzanite
| VVS |
Type 1 |
minute to not
detectable |
| VS |
Type 1 |
minor |
| SI1 |
Type 1 |
noticeable to
obvious |
| SI2 |
Type 1 |
obvious to
noticeable |
| I1 |
Type 1 |
prominent - moderate
affect on appearance or durability |
| I2 |
Type 1 |
prominent - severe
affect on appearance & durability |
| I3 |
Type 1 |
prominent - severe
affect on beauty, transparency & durability |
Type 2 Stones
-
Stones which usually contain inclusions. Most colored stones fall into this
classification.
Included in this class are:
Alexandrite
Andalusite
Corundum - Ruby and Sapphire
Garnets
Iolite
Peridot
Quartz - Amethyst
Spinel
Tourmaline - blue, orange, purple, yellow,
parti-colored
Zircon - green, orange, red, yellow
| VVS |
Type 2 |
minor |
| VS |
Type 2 |
noticeable to
obvious |
| SI1 |
Type 2 |
noticeable to
obvious |
| SI2 |
Type 2 |
obvious to prominent |
| I1 |
Type 2 |
prominent - moderate
affect on appearance or durability |
| I2 |
Type 2 |
prominent - severe
affect on appearance & durability |
| I3 |
Type 2 |
prominent - severe
affect on beauty, transparency & durability |
Type 3 Stones
-
Stones that are almost always included.
Included in this class are:
Beryl - Emerald
Tourmaline - pink to red
| VVS |
Type 3 |
noticeable to
obvious |
| VS |
Type 3 |
noticeable to
obvious |
| SI1 |
Type 3 |
obvious to prominent |
| SI2 |
Type 3 |
obvious to prominent |
| I1 |
Type 3 |
prominent -
considerable affect on appearance or durability |
| I2 |
Type 3 |
prominent - severe
affect on transparency or durability |
| I3 |
Type 3 |
prominent - severe
affect on beauty, transparency & durability |
| Declasse |
Type 3 |
stones not
transparent because of inclusions |
