Natural Emerald Cut Diamonds

An emerald cut is a step cut, not a brilliant. Instead of dozens of small facets scattering light, it has long parallel planes that behave like a hall of mirrors — flashes of white and shadow rather than sparkle. It is the most architectural of the shapes, and the least forgiving.

Forgiving of what, specifically: inclusions and colour. A round brilliant breaks light up so thoroughly that a small crystal disappears into the noise. An emerald cut does nothing of the sort. Anything inside the stone sits in an open window where you can see it. Our working floor in this shape is VS2, and we would rather drop a colour grade than a clarity grade to stay there.

Colour behaves the same way. Those long flashes carry body colour along their whole length, so a G in an emerald cut looks warmer than a G in a round. In yellow gold that is a feature. In platinum, stay at H or better.

Ratios between 1.30 and 1.50 give the classic elongated outline. Below 1.30 the stone starts to read as square — which is a real preference, not a fault, but decide on purpose.