Commonly associated with sailors and the sea, some believe this gem has protective powers and can even bring good health. The modern birthstone for March, aquamarine has become a popular gem for engagement rings, too. Watery blue to blue-green aquamarines make great additions to jewelry as well as gemstone collections.

Although these gems have a moderate price range, the best displays of their beautiful color require large stones. For buyers on a budget, synthetic pieces and alternative blue or blue-green stones may offer the best performance and value.

Aquamarine Buying and the Four Cs

The IGS aquamarine value listing has price guidelines for faceted and cabbed aquamarine.

Color

Aquamarine, the beryl variety with blue to blue-green hues, gets its color from iron speciation in the crystal. Unlike other colored gemstones, aquamarine’s value comes primarily from its tone rather than hue and saturation. Darker tones fetch higher values, and dark stones with some grey will cost more than lighter stones.

Still, light-tone stones can be quite beautiful. Some connoisseurs even prefer gems a few shades lighter than the darkest aquamarines available. However, stones called “white aquamarine” are not aquamarine and should be labeled as goshenite or colorless beryl.…