Agate and chalcedony from igneous and sedimentary hosts aged from 13 to 3480 Ma: a cathodoluminescence study

@article{Moxon2006AgateAC,
  title={Agate and chalcedony from igneous and sedimentary hosts aged from 13 to 3480 Ma: a cathodoluminescence study},
  author={Terry Moxon and Stephen J. B. Reed},
  journal={Mineralogical Magazine},
  year={2006},
  volume={70},
  pages={485 - 498}
}
  • T. Moxon, S. Reed
  • Published 1 October 2006
  • Environmental Science
  • Mineralogical Magazine
Abstract Chalcedony and agates from a variety of world-wide hosts have been examined using cathodoluminescence (CL). Gaussian fitting of the experimental data shows that there are two dominant spectral emissions at ~400 and ~660 nm. A third subordinate peak is also found at ~470, ~560 or ~620 nm. An age-related link is shown between the respective decreasing and increasing relative intensities of the 660 and 620 nm emissions. It is proposed that this change is due to a condensation reaction… 
Metamorphic effects on agate found near the Shap granite, Cumbria, England: as demonstrated by petrography, X-ray diffraction and spectroscopic methods
Abstract Agates from a 430 Ma host at Stockdale Beck, Cumbria, England have been characterized. The crystallite size of the Stockdale Beck agates was found to be ~60% greater than any other agates
Characteristics and origin of agates in sedimentary rocks from the Dryhead area, Montana, USA
Abstract Agates from the Bighorn district in Montana (USA), the so-called Dryhead area, and their adjacent host rocks have been examined in the present study. Analyses by XRD, polarizing microscopy,
A geochemical and micro-textural comparison of basalt-hosted chalcedony from the Jurassic Drakensberg and Neoarchean Ventersdorp Supergroup (Vaal River alluvial gravels), South Africa
South African basalt-hosted chalcedonies provided an ideal case study, to (a) achieve information about the origin of mineral-forming fluids, the process of chalcedony formation and weathering
Agate Genesis: A Continuing Enigma
This review covers the last 250 years of major scientific contributions on the genesis of agates found in basic igneous host rocks. From 1770 to 1955, the genesis question was frequently limited to
Agates from Kerrouchen (The Atlas Mountains, Morocco): Textural Types and Their Gemmological Characteristics
Agate nodules from Kerrouchen (Khenifra Province, Meknes-Tafilalet Region) in Morocco occur in Triassic basalts and reach up to 30 cm in diameter. Monocentric, banded agates—mainly in pastel pink,
Mineralogy, Geochemistry and Genesis of Agate—A Review
Agate—a spectacular form of SiO2 and a famous gemstone—is commonly characterized as banded chalcedony. In detail, chalcedony layers in agates can be intergrown or intercalated with macrocrystalline
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