Diamond Clarity: Eye-Clean Is the Grade That Matters
Almost every diamond carries birthmarks: tiny crystals, feathers, and clouds trapped as it formed. Clarity grading maps them at 10x magnification.
The key phrase to learn is eye-clean, meaning no marks visible to the naked eye at normal viewing distance. Two stones can sit several grades apart and both be eye-clean, with a large price gap between them.
The clarity scale
| Grade | Meaning | Practical read |
|---|---|---|
| FL / IF | Flawless / internally flawless | Collector territory. Invisible premium. |
| VVS1 / VVS2 | Very very slightly included | Marks hard to find even at 10x. |
| VS1 / VS2 | Very slightly included | Eye-clean virtually always. The sweet spot. |
| SI1 / SI2 | Slightly included | Often eye-clean. Judge the specific stone. |
| I1 to I3 | Included | Marks visible to the eye, can affect durability. |
Why the specific stone beats the grade
Two SI1 diamonds can look completely different. One has a white feather hidden near the edge where a prong will cover it. The other has a dark crystal dead center under the table. Same grade, different stones.
This is why we always say judge the diamond, not the certificate. The report's plot diagram shows where the inclusions sit, and a quick look through a loupe, or just with your eye, settles it.
Shape and size change the math
Brilliant cuts hide inclusions in their sparkle. Step cuts like emerald and Asscher hide almost nothing, so plan on VS2 or better for those shapes.
Larger stones spread their facets wider, making inclusions easier to spot. An eye-clean SI1 is common at three quarters of a carat and rarer at two carats.
Where not to compromise
- Avoid inclusions that reach the surface near the girdle, the stone's edge, where a knock could extend them.
- Avoid large dark crystals under the table, the big top facet, where they are most visible.
- Be cautious with clouds described as affecting transparency; they can make a stone look sleepy in a way photos miss.
Common questions
Is a flawless diamond a better investment?
It costs dramatically more and looks identical to a VS stone to the naked eye. Unless the certificate grade itself matters to you, that money buys more beauty elsewhere in the stone.
Can a setting hide an inclusion?
Yes, and good stone selection uses that. A mark near the edge can vanish under a prong or bezel. We do this routinely when matching stones to settings.
