pärlikihi

Pärlikihi is an Estonian term that translates to "pearl layer" or "mother-of-pearl layer." It most commonly refers to the iridescent inner lining of certain mollusk shells, such as oysters, mussels, and abalone. This layer is composed of nacre, a composite material produced by the mollusk itself to protect its soft body from foreign objects and irritants.

The distinctive shimmering or pearly luster of pärlikihi is caused by the way light interacts with the microscopic crystalline structure of the nacre. The crystals are arranged in thin, stacked sheets, and as light strikes these layers, it is reflected and diffracted, creating the iridescent effect. The colors seen can vary depending on the angle of the light and the thickness of the nacreous layers.

Historically, pärlikihi has been valued for its beauty and has been used in various forms of decoration and craftsmanship. It has been incorporated into jewelry, inlay work on furniture and musical instruments, and as embellishments on clothing and other decorative objects. The natural beauty and iridescence of pärlikihi make it a sought-after material in artisanal crafts. In some cultures, the shells containing this layer have also held symbolic or cultural significance. The formation of pearls within mollusks is a related phenomenon, where the mollusk coats an irritant with layers of nacre, eventually forming a pearl.