A shell necklace with a decorative pearl and an 18" adjustable chain embodies a coastal, natural elegance. The necklace likely features real or imitation shell elements, with each piece offering a unique iridescent shine in soft tones like white, pink, or beige. The decorative pearl, (not a real pearl), would serve as the centerpiece, adding a classic, refined touch. The pearl could be set in a delicate metal frame or suspended from a shell or metal accent. The adjustable 18" chain offers flexibility, allowing the necklace to be worn at varying lengths, making it ideal for layering or as a statement piece. This necklace would exude a beach-inspired yet sophisticated vibe, perfect for both casual and semi-formal occasions.