Mica polytypism; identification and origin

Abstract

Other| August 01, 1995 Mica polytypism: Identification and origin Hiroshi Takeda; Hiroshi Takeda University of Tokyo, Mineralogical Institute, Tokyo, Japan Search for other works by this author on: GSW Google Scholar Malcolm Ross Malcolm Ross U. S. Geological Survey, United States Search for other works by this author on: GSW Google Scholar American Mineralogist (1995) 80 (7-8): 715–724. https://doi.org/10.2138/am-1995-7-808 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Hiroshi Takeda, Malcolm Ross; Mica polytypism: Identification and origin. American Mineralogist 1995;; 80 (7-8): 715–724. doi: https://doi.org/10.2138/am-1995-7-808 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract Practical methods for identification of the complex mica polytypes have been developed by introducing a special function characteristic of their layer stacking sequences that is displayed in their X-ray diffraction patterns. This periodic intensity distribution (PID) function is the Fourier transform of a stacking sequence. The X-ray diffraction patterns of a polytype are expressed by the PID function modified by the Fourier transform of the unit mica layer. The PID function is used to determine the stacking sequences of several polytypes, and the mechanism by which the most frequently observed polytypes form is discussed. The axial settings of mica polytypes are defined in order to compute the PID functions in terms of the layer stacking sequences. Practical methods of obtaining observed PID functions are given together with tables of the PID functions of the three basic polytype series. The common polytypes have the basic sequences such as 1M, 3T, and 2M1 and are modified by a stacking fault, but the subsequent sequences are so arranged that the original direction of stacking is recovered as readily as possible. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.