Dunes Opal NecklaceActing as a wall, sand dunes along East Coast shores help protect beaches and habitats from high winds, storms, waves and tides. The dunes also provide nesting habitat to several species of seabirds and shorebirds. Shore dunes are like treasure troves of the beach's best hidden secrets. MATERIALS Ethiopian opals and clear crystal on a 16" wire with sterling silver findings finished with a sterling silver ring clasp. Every stone and shell is unique,