EX Polish

What EX Polish Means for Buyers

Polish grade measures how smooth each facet's surface is after cutting. At Excellent, no polish lines are visible even at 10× magnification. Polish becomes visible to the naked eye only at Good or worse, and even then, typically only in strong directional lighting. It's one of the least consequential of the grading dimensions.

Right now we're tracking 18,516,265 active EX polish listings across our retailer network. The typical natural EX diamond trades around $2,364/ct while the lab-grown equivalent sits at $558/ct. Roughly a 76% gap that reflects the broader natural-vs-lab pricing gap, not a quality difference at this grade.

At -30.6% above the neighboring ID grade, the premium for EX is subtle. Barely enough to move the needle on total budget. Unless you specifically want the paper grade, ID is interchangeable for most buyers and leaves money on the table for cut or carat weight.

EX shows up most often in ROUND. About 4,974,156 listings at this moment. Followed by ROUND. Most of the supply clusters around the 3.0ct+ carat range, where demand is strongest and retailers keep the deepest inventory. If you're shopping an unusual shape or carat, expect thinner selection.

Polish is cheap at the top grades, so there's rarely a reason to buy less than Very Good or Excellent. The premium is typically just a few percent over Good. On a GIA-graded stone we'd expect Excellent polish by default. Don't pay extra premiums for it, but don't accept Good or lower either.