May 12, 2011
A pearl is a hard object produced within the soft tissue (specifically the mantle) of a living shelled mollusk. Just like the shell of a mollusk, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers.Choose plate heat exchanger The ideal pearl is perfectly round and smooth, but many other shapes of pearls (baroque pearls) occur. The finest quality natural pearls have been highly valued as gemstones and objects of beauty for many centuries, and because of this, the word pearl has become a metaphor for something very rare, fine, admirable, and valuable.
Real Zhu, pearl, pearl, bead, lian bead [chemical composition] the host contains the calcium carbonate. The pearl chemical constituent becomes: CaCO391.6%th, H2O and organic matter each 4%, its 0.4%. and includes many kinds of amino acids: Leucine (Leucine), methionine (Methionine), alanin (Alanine), glycine (Glycine), glutanic acid (Glutamic acid), aspartic acid (Aspartic acid) and so on. Moreover, but also includes 30 many kinds of trace elements, the taurine, the rich Vitamin, the peptide class.
[contour characteristic] the pearl's shape are many and varied, has the circular, the pear, egg-shaped, the waterdrop shape, the button shape and the random shape, take circular as good. Heterogeneous body. The color has the white, the pink, faint yellow, the pale-green, the pale blue, brown, the lavender, the black and so on, by white primarily. White streak. Has the typical pearly luster, the gloss is gentle, and has the rainbow dizzy color. Transparently to translucent. Index of refraction 1.530-1.686, double refraction rate 0.156. Non-chromatic dispersion. Degree of hardness 2.5-4.5. The natural fresh water pearl's density is 2.66-2.78g/cm3 generally, different has the difference because of the habitat. Does not have the cleavage. Toughness compares the pearl accessories solid racket (1 good. Under the shortwave ultraviolet ray the pearl obviously white, faint yellow, the pale-green, the blue color fluorescence, the black pearl sends the light red fluorescence; Under the X-ray has the light yellow white fluorescence. Meets the hydrochloric acid to bubble.
Almost any shelled mollusk can, by natural processes, produce some kind of "pearl" when an irritating microscopic object becomes trapped within the mollusk's mantle folds, but the great majority of these "pearls" are not valued as gemstones. Nacreous pearls, the best-known and most commercially-significant pearls, are primarily produced by two groups of molluscan bivalves or clams. A nacreous pearl is made from layers of nacre, by the same living process as is used in the secretion of the mother of pearl which lines the shell.
The natural pearl assumes the round sphere, the ellipse, the anomalous sphere or the oval, the diameter 1~6 millimeters. Surface class white, yellow white, baby pink, light blue and so on, has the beautiful colored gloss, smooth. Has made the ornament pearl, central has the perforation most. The nature is hard, difficult stave, breaks delivering in person layered. With burns down it to have the report. The gas does not have, taste micro salty. the cultured pearl shape and the natural pearl are similar, but the varnish is weak, the cross section central has the circular sand grains or the abalone particles, the surface has a book nacreous layer. Is used as medicine only uses the nacreous layer.cheap wedding dresses The gas does not have, taste micro salty. However the Hepu ecology pearl's appearance greatly improved the cultured pearl quality now! take the pellet circle entire, the gloss transparent, has unusual brightness, quality of material hardness good as. [collects and processes] the whole year all produces, usually are many by December, dives the seabed, takes from the water plant or the stone goes to sea the freshwater mussel, from takes out the pearl. The meat may edible. [raw material for medicine and production and marketing] the granulated pearl which obtains for the bivalves.
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