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Facet Rough Clarity Grade Chart
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|
Grade |
Pct |
Gem |
Description |
| A |
100 |
FL |
No visible inclusions, no flaws, transparent.
|
| 99 |
IF |
No visible inclusions but in the furthermost regions from the finished cutting areas, minor stuff at the outer edges, transparent.
|
| 95 |
VVS |
Minor inclusions causing minor 5% loss of cutting region to obtain eyeclean gem, transparent.
|
| 90 |
VS |
Minor inclusions causing minor 10% loss of cutting region to obtain eyeclean gem, transparent.
|
| B |
85 |
SI1 |
Minor inclusions causing minor 15% loss of cutting region to obtain eyeclean gem, transparent.
|
| 80 |
SI2 |
Light inclusions that may not be avoidable in finished gemstone, with care they will not be easily noticed, transparent. |
| C |
75 |
I1 |
Will cut an included stone, visible to the eye. Stone may be large enough to cut away inclusions for cleaner finished gem, transparent with rare translucent areas.
|
| 70 |
I2 |
Will cut a moderately included stone, easily visible to the eye, transparent with some translucent areas.
|
| 65 |
I3 |
Will cut a heavily included stone, obvious to the eye and getting crowded, translucent with transparent areas.
|
| 60 |
Will cut a heavily included stone with sparse transparent areas, obvious to the eye and getting overcrowded, translucent with rare transparent areas.
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| D |
55 |
Will cut a very heavily included stone with few transparent areas, obvious to the eye and getting overwhelming, translucent material.
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| 50 |
Not suitable for gemstones, excellent choice for cabachons, opaque material.
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| 40 |
Not suitable for gemstones, good choice for cabachons, minimal light transmits through the stone.
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| 20 |
Stone may have a rock-like texture, or massive quality, no light transmits through the stone.
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