EX Symmetry

What EX Symmetry Means for Buyers

Symmetry grade measures how precisely the facets of the diamond align with each other, and how centred the table is relative to the girdle. Poor symmetry can distort the reflections inside the stone and slightly dull the sparkle. Excellent symmetry pairs well with an Excellent cut grade; the two tend to move together.

Right now we're tracking 20,274,893 active EX symmetry listings across our retailer network. The typical natural EX diamond trades around HK$19,130/ct while the lab-grown equivalent sits at HK$4,392/ct. Roughly a 77% gap that reflects the broader natural-vs-lab pricing gap, not a quality difference at this grade.

At -20.1% 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 5,839,803 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.

Like polish, this is cheap at the top and almost free compared to colour or clarity. Aim for Very Good or Excellent. Skip Good or lower. The facet misalignment can show in the stone's light return even if you can't name what you're seeing.