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.