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An old name for the hard, iridescent, Calcium carbonate layer form on the inside of many types of mollusk shells. The inorganic crystals are bonded by Conchiolin. Nacre layers build up over an impurity to form pearls. Colors typically include variations of white, pale yellow, pink, and gray. See Mother of pearl, and Pearl.

Synonyms and Related Terms

nácar (Esp., Port.); nacre (Fr.); Perlmutt (Deut.)

Resources and Citations

  • Maggie C. Pedersen, Gem and Ornamental Materials of Organic Origin, Elsevier, London, 2004
  • Susan E. Schur, Conservation Terminology: A review of Past & Current Nomenclature of Materials, Technology and Conservation, Spring (p.34-39); Summer (p.35-38); Fall (p.25-36), 1985
  • Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
  • The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998