Composite twins of 1M mica: derivation and identification

Access this Article

Search this Article

Author(s)

Abstract

1<I>M</I> is the simplest and one of the most common mica polytypes. Because of the special cell dimensions, twinning by reticular pseudo-merohedry is frequently observed. The possible orientations of the individuals in the twin are approximately the same as the possible orientations of layers in polytypes. Because of the presence of a pseudo-hexagonal twin lattice, five <I>pairs</I> of twin laws are possible and they give rise to five <I>pairs of corresponding twins</I>. Thirty-one composite twins can be enumerated, which however give rise to ten different diffraction patterns. In the twin lattice there are nine geometrically independent rows parallel to <B>c</B><SUP>*</SUP>, defining a <I>minimal rhombus</I> in reciprocal space, which allows us to identify the ten independent patterns. A larger unit of translation, called <I>tessellation rhombus</I>, can be built on it; by tessellation of this unit all the reciprocal space can be covered.

Journal

  • Mineralogical Journal

    Mineralogical Journal 19(4), 173-186, 1997-10-01

    Japan Association of Mineralogical Sciences

References:  49

Codes

  • NII Article ID (NAID)
    10008773025
  • NII NACSIS-CAT ID (NCID)
    AA00739590
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    05442540
  • Data Source
    CJP  J-STAGE 
Page Top