Mother of pearl, also known as nacre, is the iridescent inner layer of certain mollusk shells, such as oysters and abalones. It is composed primarily of aragonite (a form of calcium carbonate) and conchiolin (a protein), giving it a smooth, lustrous appearance. The unique play of colors, ranging from white to various shades of pink, blue, and green, is due to the way light interacts with the layered structure. Native American culture views mother of pearl as a symbol of beauty, protection, and tranquility, which adds deeper meaning to the jewelry.