Aquamarine – March’s birthstone – is known for its limpid greenish blue-to-blue color. Its name comes from two Latin words meaning “water of the sea,” and it’s said to protect both sailors and married couples from stormy waters. It often comes in large sizes and is relatively free of inclusions, leading many to associate it with purity of spirit. Fine-quality aquamarine has medium-dark blue to slightly greenish blue hues with moderately strong intensity and no visible inclusions.