Term: multilayer aggregate https://doi.org/10.1351/goldbook.M04051 Definition: A stack of lamellar crystals generated by spiral growth at one or more screw dislocations. The axial displacement over a full turn of the screw (Burgers vector) is usually equal to one lamellar thickness. Related Terms: 1) lamellar crystals (http://doi.org/10.1351/goldbook.L03446). Source: Purple Book, 1st ed., p. 82 (http://old.iupac.org/publications/books/author/metanomski.html) Citation: 'multilayer aggregate' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.M04051 License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.