mother-of-pearl

Mother-of-pearl, also known as nacre, is the iridescent inner lining of certain mollusk shells, such as oysters, mussels, and abalones. It is primarily composed of aragonite, a crystalline form of calcium carbonate, along with organic materials like conchiolin.123

The lustrous, multicolored effect, often called the "silver-lustre effect," is caused by the way light waves interact with the stratified structure of the mother-of-pearl. Light undergoes constructive and destructive interference as it reflects off the many thin layers, creating the shimmering hues. This iridescence is dependent on the number and thickness of these layers, as well as the angle from which the material is viewed.32

Historically, mother-of-pearl has been used for decorative purposes in jewelry, furniture, musical instruments, and religious objects since at least 2500 BCE. Its exceptional strength and resilience, due to its unique layered structure, have also led to research into its use in biomimetic materials for coatings and even in medical applications for bone regeneration.32