title: High abrasion resistance with sparse mineralization: copper biomineral in worm jaws.
abstract: Biominerals are widely exploited to harden or stiffen tissues in living organisms, with calcium-, silicon-, and iron-based minerals being most common. In notable contrast, the jaws of the marine bloodworm Glycera dibranchiata contain the copper-based biomineral atacamite [Cu2(OH)3Cl]. Polycrystalline fibers are oriented with the outer contour of the jaw. Using nanoindentation, we show that the mineral has a structural role and enhances hardness and stiffness. Despite the low degree of mineralization, bloodworm jaws exhibit an extraordinary resistance to abrasion, significantly exceeding that of vertebrate dentin and approaching that of tooth enamel.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA.
authors.forename: Helga C
authors.initials: HC
authors.lastname: Lichtenegger
authors.forename: Thomas
authors.initials: T
authors.lastname: Schöberl
authors.forename: Michael H
authors.initials: MH
authors.lastname: Bartl
authors.forename: Herbert
authors.initials: H
authors.lastname: Waite
authors.forename: Galen D
authors.initials: GD
authors.lastname: Stucky
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002712:Chlorides / Q000032:analysis* / Q000737:chemistry / Q000502:physiology; D002713:Chlorine / Q000032:analysis; D003300:Copper / Q000032:analysis* / Q000737:chemistry / Q000502:physiology; D003460:Crystallization; D003804:Dentin / Q000737:chemistry; D004577:Electron Probe Microanalysis; D006244:Hardness; D007568:Jaw / Q000737:chemistry; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000032:analysis*; D011077:Polychaeta / Q000033:anatomy & histology / Q000737:chemistry* / Q000502:physiology; D011506:Proteins / Q000032:analysis / Q000737:chemistry; D012542:Scattering, Radiation; D014961:X-Ray Diffraction; D014965:X-Rays
chemical_list: D002712:Chlorides; D008903:Minerals; D011506:Proteins; C111994:atacamite; D002713:Chlorine; D003300:Copper