Red Aventurine Coins with Freshwater Cultured Pearl Coins and Squares Necklace 18" The natural properties and composition of mined gemstones define the unique beauty of each piece. The image may show slight differences to the actual stone in color and texture. The natural properties and process of pearl formation define the unique beauty of each pearl. The image may show slight differences in texture, color, size and shape. Carved rings are naturally occurring imperfections that result from the pearl rotating inside the mollusk as it is growing. They define the unique beauty of each pearl and may vary in size, number and depth per pearl. Imported