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Geoscience ›› 2020, Vol. 34 ›› Issue (01): 13-14.DOI: 10.19657/j.geoscience.1000-8527.2020.01.02

• Mineralogy and Ore Deposits • Previous Articles     Next Articles

Mineral Geochemistry Characteristics and Genesis of the Multicolor Qingtian Stone from Zhejiang Province

SHEN Chonghui1(), BAI Feng2(), YANG Xiaoyan2,3, WANG Yukun4   

  1. 1. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
    2. School of Gemology,China University of Geosciences, Beijing 100083, China
    3. National Gemstone Testing Center, Shanghai 200135, China
    4. Shandong Jinchuang Co. Ltd, Penglai, Shandong 265600, China
  • Received:2019-07-12 Revised:2019-10-12 Online:2020-03-05 Published:2020-03-07
  • Contact: BAI Feng

Abstract:

Multicolor Qingtian stone is one kind of Qingtian stones from Zhejiang province, shows all kinds of colors and varied textures. In this study, based on the analysis of the petrography, X-ray powder crystal diffraction phase, whole rock major, trace elements and isotope geochemistry for the multicolor Qingtian stone, we have verified the petrologic features, mineral compositions and type divisions, and discussed the ore-forming materials, ore-forming fluids and genesis. Studies have shown that the multicolor Qingtian stone belongs to pyrophyllite-type Qingtian stone and sericite-type Qingtian stone according to the main mineral compositions. The color of the multicolor Qingtian stone is mainly related to the content of colored elements (e.g.Fe, Ti ,Cr and Mn), and has a little of relationship with mineral microcrystalline particles and micro-cracks of hematite (limonite) impregnation of constituent minerals. The ore-forming materials of the multicolor Qingtian stone sourced from medium-acid volcanic rock, and ore-forming fluids sourced from meteoric waters. The multicolor Qingtian stone is mainly composed of filling-genesis pyrophyllite in the early stage and sericite that formed by medium-low temperature hydrothermal alteration on the filling-genesis pyrophyllite in the late stage. It derived from multi-period and multi-stage of hydrothermal alteration metasomatism. Multicolor Qingtian stone often retains high temperature mineral andalusite.

Key words: multicolor Qingtian stone, petrography, pyrophyllite, andalusite, sericite

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