Mother of pearl

Perl-kohle,/. pea eoal. -koks, m. eoke breeze, -leim, m, pearl glue, -moos, n. pearl moss, earrageen. -mutter, /. mother-of-pearl, naere. 

Perlmutter-blech, n. erystallized tinplate, moir6 m4tallique. -glanz, m. mother-of-pearl luster, naereous luster. 

And purchase fine merchandise, Mother-of-pearl and corals, amber and ebony, And pleasurable perfumes of all kinds,... 

FIGURE 19.15 A photomicrograph of the cross section of the mother-of-pearl lining a mollusk shell. The composite material making up mother-nf-pearl consists of flat crystals of calcium carbonate embedded in a tough, flexible organic matrix that resists cracking. 

Shell is the term generally used to refer to the hard exoskeleton of some animals, such as the mollusks, as well as to the protective covering of the eggs of birds and some amphibians and reptiles. The shell of many mollusks, for example, consists of three layers the innermost is a shiny layer of nacre, also known as mother of pearl, which includes a mixture of the mineral arag-... 

The basic constituent of seashells is calcium carbonate, an insoluble compound formed from calcium ions secreted from the cells of the shellfish and carbonate ions present in seawater. But calcium carbonate is a white solid. The colors of seashells often arise from impurities and metabolic waste products captured in the solid shell as it is formed. Coloration is dictated by both diet and water habitat. For example, some cowries that live and feed on soft corals take on the hue of the coral species. Yellow and red colors often arise from carotenoid pigments such as //-carotene. Light refraction often generates the iridescent mother-of-pearl hues. 

Tyndall scattering also causes the blinding effect of shining a car headlight directly into a thick bank of fog or mist it also yields the beautiful iridescent colours on the wing of a butterfly or peacock tail, and an opal and mother of pearl. A good potter can reproduce some of these optical effects with so-called iridescent glazes, which comprise colloidal materials. 

The distillate is at once extracted with ether and the extract, after having been separated from the water, is heated on the water bath until most of the ether has distilled. The residue, which contains unchanged phenol as well as the salicylaldehyde, is now vigorously shaken in a small glass-stoppered bottle with two volumes of concentrated commercial sodium bisulphite solution. A thick paste of the bisulphite compound of the aldehyde is formed. After this paste has stood for from half an hour to one hour the bisulphite compound is separated by filtration at the pump, pressed well on the filter funnel, and washed several times, first with alcohol and finally with ether, until completely free from adherent phenol. The crystals (small plates, iridescent like mother-of-pearl) are then decomposed with dilute sulphuric acid in a small round-bottomed flask whi( h is fitted with an air condenser and gently warmed on the water bath. After the liquid thus produced has cooled, the aldehyde which separates is extracted with ether and the ethereal solution is dried with anhydrous sodium sulphate. The pure aldehyde which remains when the ether is evaporated distils at 196°. The yield amounts to 10-12 g. 

Dihydrazone Oxamide forms salts, such as Hydrochloride, C2HgNg.2HCI, yel ndls,swells w/o melting, more stable than its parent compd Nitrate, C2HgN. 2HNO 3, mother-of-pearl-coJored cryst... 

Wise, S. W. Microarchitecture and mode of formation of nacre (mother of pearl) in pelece-pods, gastropods and cephalopods. Eclogae geol. Helv. 63, 775 (1976)... 

I purpose to call it margarine, from the Greek word signifying pearl, because one of its characters is to have the appearance of mother of pearl, which it communicates to several of the combinations of which it forms with the salifiable bases. 

The next insight came as an image of an oyster shell, with the mother-of-pearl shining in different colors. I translated that in the idea of an interferometer—two layers separated by a gap equal to the wave length it is desired to reflect."... 

On 20 May 1992, a Dutch periodical published an article in which they mentioned the possibility of healing fractures with mother-of-pearl and coral. With this method painful operations could be avoided. The article was illustrated with an ancient Maya skull which showed a hole filled with mother-of-pearl. The ancient Mayas were well ahead of their time. 

Yet another product of the sea is a huge oyster found south of the Philippine island Palawan. It is called Pinctada maxima and can weigh up to ten kilogrammes. This oyster produces a shell which is as strong as reinforced vibrated concrete. Like coral, this shell is made of calcium carbonate. The inside is covered with mother-of-pearl which cannot be digested by human bone cells. Mother-of-pearl consists for approximately 66% of calcium carbonate and for about 31% of water. The rest is conchioline, a though and homy product. 

The surface of the mother-of-pearl is somewhat permeable for human cells and consequently these cells can form a strong bond between the mother-of-pearl and the bone. Mother-of-pearl is also used in the manufacture of artificial dental roots. These can be attached to the jaw much more firmly than any metal whatsoever. It is thought that mother-of-pearl contains certain natural substances which accelerate the production of human bone. 

Calcium carbonate, mother-of-pearl, magnesite, dolomite and other inorganic materials which nature uses to provide an organism with solidity, have been categorized under the name bioceramic materials. Later some synthetic materials were added to this group. This means that the definition of a ceramic material, as given at the beginning of this book, must somewhat be adjusted as the heat treatment of a ceramic material obviously does not apply in the animal world. 

A particularly well-studied structure is that of the nacreous layer (= Mother-of-Pearl) of molluscs, which will be used below to illustrate our concepts17 34,46,233-241). 

Gregoire, Ch., and Lorent, R. Alterations in conchiolin matrices of mother-of-pearl during conversion of aragonite into calcite under experimental conditions of pyrolysis and pressure. Biomineralisation 6, 70-83 (1972). 

Voss-Foucart, M. F., and Gregoire, Ch. On biochemical and structural alterations in fossil and pyrolysed modern mother-of-pearl. Biomineralisation 6, 134—140 (1972). 

Pearls are little spheres of calcium carbonate (CaC03) that form in mol-lusks (invertebrate shellfish) such as oysters, usually because of some sort of irritation. They are normally white or off-white in color, but they can have bluish or pink tints, and sometimes they are dark gray. Although many pearls form naturally, pearl production has been gready increased by the cultured pearl industry, which raises beds of oysters into which irritants are routinely introduced. The irritants are usually bits of mother-of-pearl, the lining that forms inside oyster shells. 

Grips maybe made of wood, plastic, laminated phenolic resin, or rubber, and rubber is also used for recoil pads. Customized or ornamental firearms may have grips made from ivory mother of pearl, or buffalo horns, and the firearm may have elaborate engraving some of which is inlaid with gold or silver. Such firearms are unlikely to be used in crime. 

A 30 or 40 per cent by volume hydrogen peroxide is used as bleach for silk, wood, Wool, bones, teeths, feathers, mother of pearl, hom, hair, coral, gelatine, oils and fats. In medical science it is an excellent disinfectant and is also essential for sterilizing water for municipal use and preserving milk. Apart from this, hydrogen peroxide is used in the chemical industries for the manufacture of persalts and in laboratories for oxidation. 

---