Electron Microscope Study of Brazil Twin Boundaries in Amethyst Quartz

Abstract

Abstract A study has been made of the diffraction contrast fringe patterns observed by transmission electron microscopy in amethyst quartz. Evidence is presented that the fringe patterns are due to Brazil twin boundaries on {10 1 1} planes. A model for the Brazil twin boundary which does not involve the breaking of SiO bonds is proposed and shown to be consistent with the fringe patterns observed with different operating reflections.