How to judge an emerald

Three parameters describe it, the hue, the saturation and the tone. The hue says where the green sits between yellow and blue, the saturation says how strong it is, the tone says whether it is light or dark. The top of the market sits on a pure to slightly bluish green, strongly saturated, neither washed out nor darkened.

Colombian deposits have recognizable signatures. Muzo leans toward a deep green with a bluish edge, Coscuez slightly less bluish, Chivor a fresher green. A Zambian stone pushes toward a bluer, darker, colder green. At equal weight, strong saturation without darkening weighs more than everything else combined.

The setting where an emerald crystallizes is turbulent, and fissures form while it grows. The set of these internal features is called the garden. Their presence is expected. A complete absence should instead raise doubt about the natural origin of the stone.

What counts is not their number but their effect. An inclusion that clouds transparency costs a great deal in value, a discreet one takes nothing away. A fissure that reaches the surface and runs through the stone is a soundness problem, not a cosmetic one. On a Colombian stone, the three-phase inclusion serves as an origin marker, a gas bubble and a salt crystal trapped in a pocket of liquid.

The rectangular step cut is named the emerald cut, and it does not come from an aesthetic choice. Its cut corners protect the angles, the weak point of a fragile stone, and its steps let the color show in depth rather than making it sparkle.

The oval and the cushion round off the outline and rescue an irregular rough. The cabochon, polished without facets, suits heavily included stones whose transparency rules out faceting. A cut that is too deep kills the color, a cut that is too shallow lets the light pass through without coming back. Weight retention matters too: a cutter who keeps weight at the expense of proportion produces a heavy, dull stone.

A carat weighs 0.2 gram. Two stones of the same weight can look very different depending on their cut, which is why the dimensions in millimeters matter as much as the carat.

Below two carats, color carries almost all of the value and weight follows. Above that, an intense color becomes rare and the price climbs in steps. Across the 46 stones available in our catalog on 18 September 2026, prices run from €200 to €29,300 including tax, or €197 to €6,296 per carat, with a median of €1,077 per carat. The spread comes from color first, not from weight.

Almost every emerald on the market receives a filling of its open fissures, oil or resin. The product fills the openings and makes the stone easier to read. The practice is long-standing and accepted, provided it is declared.

The laboratory measures two distinct things. The nature of the product first, oil or resin. The amount found next, from none to significant through insignificant, minor and moderate. A degree says nothing about the nature, and a nature says nothing about the degree. A stone sold as untreated while its report records minor oil is a stone described wrongly.