The Emerald Buyer's Guide

The finest Colombian emeralds show a pure, vivid green with a slightly bluish undertone, a medium to medium-dark tone and strong saturation. Stones that are too light, too dark or leaning towards yellow are valued lower. Colour should always be judged in neutral daylight.

Price per carat rises sharply with size, because fine material above 2 ct is rare. Two stones of the same weight can differ widely in value: carat weight only counts once colour and clarity are right.

Almost every natural emerald contains inclusions — the jardin, or garden. They are expected and help confirm natural origin. What matters is whether they affect brilliance or durability, and the type and degree of any clarity enhancement, which should always be disclosed.

The classic emerald cut protects the stone and shows its colour evenly, but ovals, cushions, rounds and pears are also common. A good cut balances weight retention with brilliance, symmetry and an even distribution of colour.