Pathfinder Wiki - User contributions [en]

AY Honors/Shells - Advanced/Answer Key

2005-07-23T03:45:30Z

24.238.128.166:

[[image:nacre.jpg|thumb|A piece of nacre]]

'''Nacre''', also known as '''mother of pearl''' or '''sadaf''', is an organic mixture of [[calcium carbonate]] (CaCO<sub>3</sub>) in the form of platy crystals of [[aragonite]] and [[conchiolin]] (a [[scleroprotein]]).

Nacre is secreted by the [[ectoderm|ectodermic]] [[cell (biology)|cells]] of the [[Mantle (mollusc)|mantle tissue]] of certain species of [[mollusk]]. In these mollusks, nacre is continually deposited onto the inner surface of the animal's shell (the [[iridescent]] ''nacreous layer'', commonly known as ''mother of pearl''), both as a means to smooth the shell itself and as a defense against [[parasite|parasitic organisms]] and damaging detritus.

The iridescent inner layer is considered highly attractive by many cultures and is often used in making [[jewlery]] or as inlays in wood [[furniture]] and [[guitar]]s.

When a mollusk is invaded by a [[parasite]] or is irritated by a foreign object that the animal cannot eject, a process known as ''[[encystation]]'' entombs the offending entity in successive, concentric layers of nacre. This process eventually forms what we call [[pearl]]s and continues for as long as the mollusk lives.

==Research==

*Lin, A., and Meyers, M.A. 2005. Growth and structure in abalone shell, ''Materials Science and Engineering A'' '''390'''(Jan. 15):27–41 (see [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TXD-4DH2DRS-1&_coverDate=01%2F15%2F2005&_alid=256050522&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5588&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=f4efd0a3d7cf3b4a0b8f9861cff4514d abstract])

== See also ==
* [[Ammolite]]

[[Category:Molluscs]]
{{Wiktionary}}

[[de:Perlmutt]]
[[pl:Masa perłowa]]

AY Honors/Shells - Advanced/Answer Key

2005-07-23T03:45:16Z

24.238.128.166:

[[image:nacre.jpg|thumb|A piece of nacre]]

'''Nacre''', also known as '''mother of pearl''' or ''sadaf'', is an organic mixture of [[calcium carbonate]] (CaCO<sub>3</sub>) in the form of platy crystals of [[aragonite]] and [[conchiolin]] (a [[scleroprotein]]).

Nacre is secreted by the [[ectoderm|ectodermic]] [[cell (biology)|cells]] of the [[Mantle (mollusc)|mantle tissue]] of certain species of [[mollusk]]. In these mollusks, nacre is continually deposited onto the inner surface of the animal's shell (the [[iridescent]] ''nacreous layer'', commonly known as ''mother of pearl''), both as a means to smooth the shell itself and as a defense against [[parasite|parasitic organisms]] and damaging detritus.

The iridescent inner layer is considered highly attractive by many cultures and is often used in making [[jewlery]] or as inlays in wood [[furniture]] and [[guitar]]s.

When a mollusk is invaded by a [[parasite]] or is irritated by a foreign object that the animal cannot eject, a process known as ''[[encystation]]'' entombs the offending entity in successive, concentric layers of nacre. This process eventually forms what we call [[pearl]]s and continues for as long as the mollusk lives.

==Research==

*Lin, A., and Meyers, M.A. 2005. Growth and structure in abalone shell, ''Materials Science and Engineering A'' '''390'''(Jan. 15):27–41 (see [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TXD-4DH2DRS-1&_coverDate=01%2F15%2F2005&_alid=256050522&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5588&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=f4efd0a3d7cf3b4a0b8f9861cff4514d abstract])

== See also ==
* [[Ammolite]]

[[Category:Molluscs]]
{{Wiktionary}}

[[de:Perlmutt]]
[[pl:Masa perłowa]]