Definition of Nacre
For nacre it means the iridescent coating on the inner part of some species of molluscs and composed of aragonite and calcite, a polymorph of calcium carbonate. The nacre is also the main material used in the manufacture of a pearl nucleus .
The Forms of Mother of Pearl Shells inside
Famous for its sparkling beauty around the world, the iridescent material known as nacre is organic / inorganic substance that lines the inside of the shell of a mollusk. The play of colors that is produced on the surface of the inner lining, also known as luster, is an optical phenomenon where the wavelengths of light are scattered and refracted again toward the observer returning a gloss effect.
As long as there has been over the plastic, in the mid-20th century, the pearl was also used for the production of glossy buttons in the clothing field. This was the case happened in broome, Australia, a known area of production of south sea pearls. Before the Australian pearls, this small town has prospered thanks to the marketing of mother of pearl pinctada maxima.
The Use of Mother of Pearl in Cultured Pearls
The nacre is now widely used as a pearl farming nucleus. The shell of a mussel is cut into squares and then worked through a process which rounds the pieces to create the marbles. These marbles are then implanted in the oyster, which then secrete nacre on pearly beads to form the final cultured pearl defined by MATHGENERAL.
The pearl has two functions: it offers protection from predators, and provides shelter from the elements. The shielding of the shellfish from predators and parasites is a process called “encystment”. Nacre generated by defending molluscs from parasites, as a result of an irritant reaction, it is capable of giving life to the rarest of treasures: a pearl.
The Growth of a Shell
Nacre provides shelter to clam soft body, the strength and resilience of the shell allows the animal to survive the incessant environmental pressures and difficulties of its habitat. The structure of a shell begins with an oval fate, in rounded form and called shape. The shape is gradually surrounded by concentric rings of growth of nacre that thickens and widening continuously outwards el order to accommodate the animal for all his life.
The Shell Structure
The Shell of a Mollusc is Constituted by Three Layers Core:
– the periostracum: this is the outer layer, the horny-looking, this is made from conchiolin (a complex of proteins, different from keratin or collagen), secreted by glands which are located at the edge of the mantle and which is deposited at the margins man hand the shell increases its mass. It is the first layer that forms around the mollusk.
The Next Two Layers Form the Ostraco:
– Layer prismatic, at the intermediate level and often and consists of several layers, this also secreted from the edge of the mantle. Formed by hexagonal prisms of calcium carbonate in their turn surrounded by conchiolin. Contrary to its name, this layer is not iridescent, it particularly beautiful and plays the role of stabilizing the internal layer.
– Inner layer or pearly: formed by parallel lamellae of calcium carbonate, is secreted by the whole surface of the coat. It is the final layer of the shell and exhibits the colors and iridescence. The nacre growth is very slow in the pinctada margaritifera, while in the other molluscs the rate of growth depends on the environment in which crystalline live.
The aragonite platelets are transparent and mimic the wavelengths of visible light, this allows the absorption of light rays, scattered and reflected back to the observer in various shades with the consequent phenomenon of iridescence. The word iridescence comes from the greek word “iris” and translates as “rainbow” (rainbow). Greek legend portrays the ancient goddess iris, personified as bright colorful arc, while announcing the divine proclamations from olympus to the mortals who worshiped her as a spiritual adviser.
Although now, thanks to science, we can explain what is behind the effect of iridescence, it does not make it less attractive or stimulating phenomenon in the imagination of people around the world.