New Technique and Indicators for Studies of Growth History of Zoned Crystals.

Abstract

Two X-ray diffraction imaging techniques have been applied for the first time to the study of previously unnoted mosaic detail in color-zoned Brazilian tourmaline. The divergence source-image distortion (DSID) technique gives maximum values for misorientations among all observable grains, whereas the convergence source-image distortion (CSID) technique yields the magnitude of misorientation between adjacent grains. Strikingly abrupt textural changes are observed; they are always accompanied by color changes. The converse is not found to hold. The central or core region of all five plates studied shows a macromosaic texture. No grain elongation is observed. AT-cut quartz crystals can be made to Dauphine twin by torsion at above 600C, such that the twin boundaries assume veil-like shapes with steps, except where they correspond to pre-existing growth horizon boundaries. Strain rate controls and recording are needed to exclude problems with fracturing. (Author)

Document Details

Document Type
Technical Report
Publication Date
Aug 31, 1973
Accession Number
AD0767437

Entities

People

  • Charles O. Pollard Jr

Organizations

  • Georgia Tech Research Corporation

Tags

DTIC Thesaurus Topics

  • Boundaries
  • Convergence
  • Diffraction
  • Distortion
  • Elongation
  • Imaging Techniques
  • Indicators
  • Shape
  • Strain Rate
  • X Rays
  • X-Ray Diffraction

Readers

  • Image Processing and Computer Vision.
  • Materials Science (Mechanical Engineering).
  • Materials Science and Engineering.