Nacre
Nacre (
Nacre is found in some of the most ancient lineages of
The outer layer of cultured pearls and the inside layer of
Physical characteristics
Structure and appearance
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Biomineralization |
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Nacre is composed of hexagonal platelets of
).Nacre appears
The crystallographic c-axis points approximately perpendicular to the shell wall, but the direction of the other axes varies between groups. Adjacent tablets have been shown to have dramatically different c-axis orientation, generally randomly oriented within ~20° of vertical.[4][5] In bivalves and cephalopods, the b-axis points in the direction of shell growth, whereas in the monoplacophora it is the a-axis that is this way inclined.[6]
Mechanical properties
This mixture of brittle platelets and the thin layers of elastic biopolymers makes the material strong and resilient, with a
A variety of toughening mechanisms are responsible for nacre's mechanical behavior. The
When dehydrated, nacre loses much of its strength and acts as a brittle material, like pure aragonite.[13] The hardness of this material is also negatively impacted by dehydration.[13] Water acts as a plasticizer for the organic matrix, improving its toughness and reducing its shear modulus.[13] Hydrating the protein layer also decreases its Young's modulus, which is expected to improve the fracture energy and strength of a composite with alternating hard and soft layers.[15]
The statistical variation of the platelets has a negative effect on the mechanical performance (stiffness, strength, and energy absorption) because statistical variation precipitates localization of deformation.[19] However, the negative effects of statistical variations can be offset by interfaces with large strain at failure accompanied by strain hardening.[19] On the other hand, the fracture toughness of nacre increases with moderate statistical variations which creates tough regions where the crack gets pinned.[20] But, higher statistical variations generates very weak regions which allows the crack to propagate without much resistance causing the fracture toughness to decrease.[20] Studies have shown that this weak structural defects act as dissipative topological defects coupled by an elastic distortion.[21]
Formation
The process of how nacre is formed is not completely clear. It has been observed in Pinna nobilis, where it starts as tiny particles (~50–80 nm) grouping together inside a natural material. These particles line up in a way that resembles fibers, and they continue to multiply.[22] When there are enough particles, they come together to form early stages of nacre. The growth of nacre is regulated by organic substances that determine how and when the nacre crystals start and develop.[23]
Each crystal, which can be thought of as a "brick", is thought to rapidly grow to match the full height of the layer of nacre. They continue to grow until they meet the surrounding bricks.[6] This produces the hexagonal close-packing characteristic of nacre.[6] The growth of these bricks can be initiated in various ways such as from randomly scattered elements within the organic layer,[24] well-defined arrangements of proteins,[2] or they may expand from mineral bridges coming from the layer underneath.[25][26]
What sets nacre apart from fibrous aragonite, a similarly formed but brittle mineral, is the speed at which it grows in a certain direction (roughly perpendicular to the shell). This growth is slow in nacre, but fast in fibrous aragonite.[27]
A 2021 paper in Nature Physics examined nacre from Unio pictorum, noting that in each case the initial layers of nacre laid down by the organism contained spiral defects. Defects that spiralled in opposite directions created distortions in the material that drew them towards each other as the layers built up until they merged and cancelled each other out. Later layers of nacre were found to be uniform and ordered in structure.[21][28]
Function
Nacre is secreted by the
In different mollusc groups
The form of nacre varies from group to group. In
Commercial sources
The main commercial sources of mother of pearl have been the
Widely used for pearl buttons especially during the 1900s, were the shells of the great green
Uses
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Seashells |
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Mollusc shells |
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Decorative
Architecture
Both black and white nacre are used for
Musical instruments
Nacre inlay is often used for music
Indian mother of pearl art
At the end of 19th century,
Other
Mother of pearl buttons are used in clothing either for functional or decorative purposes. The Pearly Kings and Queens are an elaborate example of this.
It is sometimes used in the decorative grips of firearms, and in other gun furniture.[citation needed]
Mother of pearl is sometimes used to make spoon-like utensils for caviar (i.e. caviar servers[38][39]) so as to not spoil the taste with metallic spoons.
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Altarpiece, c. 1520, with extensive use of carved nacre
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tesserae, Topkapı Palace, Istanbul
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Engraved nacre pendant, Solomon Islands 1838
Biomedical use
The biotech company Marine Biomedical, formed by a collaboration between the
Manufactured nacre
In 2012, researchers created calcium-based nacre in the laboratory by mimicking its natural growth process.[41]
In 2014, researchers used lasers to create an analogue of nacre by engraving networks of wavy 3D "micro-cracks" in glass. When the slides were subjected to an impact, the micro-cracks absorbed and dispersed the energy, keeping the glass from shattering. Altogether, treated glass was reportedly 200 times tougher than untreated glass.[42]
See also
References
- ^ "nacre". Dictionary.com Unabridged (Online). n.d.
- ^ PMID 16413789.
- OCLC 664839176.
- PMID 17678131.
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- ^ S2CID 10214928.
- ^
Jackson, A. P.; Vincent, J. F. V; Turner, R. M. (1988). "The mechanical design of nacre". Proceedings of the Royal Society B: Biological Sciences. 234 (1277) (published 22 Sep 1988): 415–440. S2CID 135544277.
- PMID 31645557.
- .
- .
- PMID 17315945.
- S2CID 135681723.
- ^ ISSN 2046-2069.
- ISSN 0022-5096.
- ^ S2CID 55616061.
- ^ ISSN 0928-4931.
- ^ S2CID 139307131.
- S2CID 219464365.
- ^ a b Abid, N.; Mirkhalaf, M.; Barthelat, F. (2018). "Discrete-element modeling of nacre-like materials: effects of random microstructures on strain localization and mechanical performance". Journal of the Mechanics and Physics of Solids. 112: 385–402. .
- ^ a b
Abid, N.; Pro, J. W.; Barthelat, F. (2019). "Fracture mechanics of nacre-like materials using discrete-element models: Effects of microstructure, interfaces and randomness". Journal of the Mechanics and Physics of Solids. 124: 350–365. S2CID 139839008.
- ^ a b
Beliaev, N.; Zöllner, D.; Pacureanu, A.; Zaslansky, P.; Zlotnikov, I. (2021). "Dynamics of topological defects and structural synchronization in a forming periodic tissue". Nature Physics. 124 (3): 350–365. S2CID 230508602.
- PMID 26631940.
- PMID 19915030.
- PMID 16315200.
- .
- PMID 21982842.
- ^ Bruce Runnegar & S Bengtson. "1.4" (PDF). Origin of Hard Parts — Early Skeletal Fossils.
- ^ Meyers, Catherine (January 11, 2021). "How Mollusks Make Tough, Shimmering Shells". Inside Science. Retrieved June 9, 2021.
- ^ John, James St (2007-07-31). Fossil nautiloid shell with original iridescent nacre in fossiliferous asphaltic limestone (Buckhorn Asphalt, Middle Pennsylvanian; Buckhorn Asphalt Quarry, Oklahoma, USA) 1 (photo). Retrieved 2023-01-09 – via Flickr.
- ^ Jessica Hodin (October 19, 2010). "Contraband Chic: Mother-of-Pearl Items Sell With Export Restrictions". The New York Observer. Archived from the original on 2010-10-24. Retrieved 2023-01-09.
- ^ "Anukul Charan Munshi, the Maverick of Indian Mother-of-Pearl Artistry". Calcutta, India: Wixsite.com. February 5, 2005. Retrieved Sep 22, 2022.
- ^ "Anukul Charan Munshi". Calcutta, India: Arthive. February 5, 2005. Retrieved Sep 22, 2022.
- ^ "Poster by Annada Munshi for ITMEB, 1947". Urban History Documentation Archive, Centre for Studies in Social Sciences, Calcutta. Retrieved 24 December 2023 – via Researchgate.
- ^ Anandabazar Patrika. "Munshiana" Publisher: Anandabazar Patrika
- ^ "Artist Manu Munshi, Renowned Mother of Pearl Artist of India". Calcutta, India: Wixsite.com. February 5, 2005. Retrieved Sep 22, 2022.
- ^ Santanu Ghosh. "Binodane Paikpara Belgachia". Dey's Publishing. Retrieved 24 December 2023.
- ^ Santanu Ghosh. "Munshianay Chollis Purush" Publisher: Dey's Publishing
- ^ "Ceto the Shrimp - Plate". Objet Luxe. Retrieved 2021-07-14.
- ^ "Crab Caviar Server". Objet Luxe. Retrieved 2021-07-14.
- ^ Fowler, Courtney (28 October 2021). "Kimberley mother-of-pearl could become synthetic bone in world-first medical collaboration". ABC News. Australian Broadcasting Corporation. Retrieved 29 December 2021.
- S2CID 9004843.
- ^ "Super-tough glass based on mollusk shells". Gizmag.com. 30 January 2014. Retrieved 2014-02-13.
Further reading
- Abid, N.; Mirkhalaf, M.; Barthelat, F. (2018). "Discrete-element modeling of nacre-like materials: Effects of random microstructures on strain localization and mechanical performance". Journal of the Mechanics and Physics of Solids. 112: 385–402. .
- Bruet, B.; Qi, H.J.; Boyce, M.C.; Panas, R.; Tai, K.; Frick, L.; Ortiz, C. (2005). "Nanoscale morphology and indentation of individual nacre tablets from the gastropod mollusc Trochus niloticus" (PDF). J. Mater. Res. 20 (9): 2400. S2CID 564507.
- Checa, Antonio G.; .
- Frýda, J.; Bandel, K.; Frýdová, B. (2009). "Crystallographic texture of Late Triassic gastropod nacre: evidence of long-term stability of the mechanism controlling its formation". .
- Lin, A.; Meyers, M.A. (2005-01-15). "Growth and structure in abalone shell". Materials Science and Engineering A. 390 (1–2): 27–41. .
- Mayer, G. (2005). "Rigid biological systems as models for synthetic composites". Science. 310 (5751): 1144–1147. S2CID 19079526.