On the change of color of blue opal

DOI
  • Hayashi Masahiko
    Kawanami Center for Learning Resources, Information and Communication, Seitoku University
  • Ando Yasuyuki
    Research Institute for Science and Engineering, Waseda University
  • Yasui Mana
    Research Institute for Science and Engineering, Waseda University
  • Yamazaki Atsushi
    Department of Resources and Environmental Engineering, School of Creative Science and Engineering, Waseda University

Bibliographic Information

Other Title
  • ブルー・オパールの変色について

Abstract

The blue Opal is a very attractive color. We analyzed the X-ray powder diffraction experiment and chemical compositions by EPMA. <br> (1) X-ray powder diffraction experiment:<br> ・X-ray diffractometer Rigaku RINT ULTIMA3<br> ・X ray source:Cu Kα<br> ・voltage / current: 40kV/20 mA<br> Result<br> Diffraction patterns show Opal-CT.<br> (2) EPMA:<br> ・Japan e-JSM-6360 + OXFORD INCA EDS<br> ・Acceleration voltage: 15 kV<br> ・Ｒange: 20 mm<br> ・Total time: 60 sec<br> Result<br> Copper and chlorine were found<br> As the result, this opal is opal-CT. And the blue cause is in a copper (II) chloride. This blue is the mineral eriochalcite ( CuCl2･2H2O ). Blue dries and turns into yellow. Yellow is CuCl2.<br> The blue Opal have to be cautious of discoloring.

Journal

Details 詳細情報について

  • CRID
    1390001205595495296
  • NII Article ID
    130004729824
  • DOI
    10.14915/gsj.34.0.6.0
  • Text Lang
    ja
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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