About how many millimeters thick is the nacre (mother-of-pearl) layer?
The shiny surface of a pearl is called the nacre layer, and it is about 0.5 to 1 mm thick. It is made of many layers of thin, hexagonal calcium crystals. A single crystal sheet is about 0.4 microns thick. If the nacre layer is 1 mm thick, it means as many as 2,500 of these thin sheets are stacked together.
What is conchiolin?
The pearl’s luster comes from a protein called “conchiolin.” Conchiolin protein has properties similar to collagen. It is used as a beauty ingredient for skin and hair because it helps prevent wrinkles and fine lines.