Mother of Pearl Buttons:
Mother of pearl, also known as nacre, is an iridescent layer of material that forms the shell lining of creatures like many mollusks. Pearl oysters and abalone also provide the mother of pearl look from their shells. The charming look of nacre allows a wide range of application like the inlay in jewelry, furniture, and musical instruments. Mother of pearl comes in several natural colors, but is often bleached and dyed for decorative use. The dye retains the shimmering layers which make the material so sought after. Nacre is a tough and resilient material, and is good for making genuine pearl buttons.
The iridescence that makes nacre so attractive results is because of the "aragonite" crystals of the shell which have a range of thicknesses that are close to the wavelengths of visible light. Some of the light that strikes the crystalline layers will go through to the layers below, while some is reflected from the upper and the lower surfaces. Layers tend to reflect particular wavelengths, that is, colors, depending on their thickness and on the angle of the light. When viewed from different angles, different colors are reflected. Small irregularities on the surfaces make every piece of nacre unique.

