This art deco inspired necklace features a central round milky aquamarine gemstone surrounded by glistening marcasite stonesderived from the latin aqua meaning water and mare meaning sea aquamarine has a longstanding relationship with all things aquatic it has been said that sailors used to keep aquamarine aboard on long journeys to protect them from the dangers at sealining the focal aquamarine gemstone is the natural semi precious gemstone marcasite once used by some as a substitute