Yankuang ceshi (Jul 2020)

Application of X-ray Powder Diffraction Method in Identification and Classification of Leptite

  • WU Yue,
  • CHI Guang-cheng,
  • LIU Xin

DOI
https://doi.org/10.15898/j.cnki.11-2131/td.201908050117
Journal volume & issue
Vol. 39, no. 4
pp. 546 – 554

Abstract

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BACKGROUND The identification of leptite is usually based on microscopic identification technology, but it is very difficult to distinguish tiny feldspar, quartz, and layered silicate minerals such as chlorite, montmorillonite and mica using a microscope. There could be a large error in the naming of leptite by microscopic identification methods, which will cause errors in geological mapping and original rock recovery, leading to incorrect geological conclusions. The development of X-ray powder diffraction analysis technology has led to its wide use in the study of mineralogy and petrology. OBJECTIVES To identify tiny minerals that are difficult to distinguish under the microscope by using X-ray powder diffraction technology. METHODS A total of 23 leptite samples were selected. The mineral composition of leptite was detected by X-ray powder diffraction analysis and microscopic rock thin section identification technology. Semi-quantitative X-ray powder diffraction was used to verify the accuracy of the rock slice identification results. RESULTS The comparison between the identification results of the microscopic rock slices and the X-ray powder diffraction phase analysis results showed that 10 out of 23 samples had the same name. Analyzing the reasons for the difference, it can be found that the advantage of microscopic rock identification was that it can be used to determine rock texture and structure, as well as common mineral components. The advantage of the X-ray powder diffraction method was that it can be used to detect the relative content of tiny quartz and feldspar particles that were difficult to distinguish under the microscope, and can detect tiny layered silicate minerals such as chlorite, montmorillonite and mica, which was effective for detecting minerals with less content and finer particles. CONCLUSIONS Only by combining the microscopic rock thin identification technology and the X-ray powder diffraction technology can the leptite be named and classified more accurately. The combination of two techniques provides more objective technical data and analytical conclusions for geoscience research.

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