Like many stones, the per-carat price of fine quality emerald escalates rapidly with size. For example, a recent price guide lists a fine quality 3-ct Colombian stone as six times more valuable than three equivalent quality 1-ct stones.

Value factors hinge largely on color, with nuances of saturation and hue affecting price to a significant degree. The most desirable color is a slightly bluish green in a medium dark tone with strong to vivid saturation.

Quick Facts

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Mineral: Beryl

Chemistry: Be3Al2Si6O18

Color: Vibrant green

Refractive Index: 1.577 to 1.583

Birefringence: 0.005 to 0.009

Specific Gravity:   2.72

Mohs Hardness: 7.5 to 8