Spectroscopy and Spectral Analysis, Volume. 38, Issue 6, 1753(2018)

In-Situ Raman Spectroscopy Testing and Genesis of Graphite Inclusions in Alluvial Diamonds from Hunan

MA Ying1, WANG Qi2, QIU Zhi-li1, LU Tai-jin3, LI Liu-fen1, CHEN Hua3, DENG Xiao-qin1, and BO Hao-nan1
Author Affiliations
  • 1[in Chinese]
  • 2[in Chinese]
  • 3[in Chinese]
  • show less

    Graphite is one of the most common inclusion in diamond, it can be divided into protogenetic, syngenetic and epigenetic on the basis of sequence of graphite inclusion formation. The formation environment of the diamond and its late change are indicated by protogenetic/syngenetic and epigenetic graphite. In-situ microscopic laser Raman spectroscopy, we carried out on graphite inclusions in 13 gem-grade and semiprecious alluvial diamonds from the the Yuanjiang Basin in Hunan province(Yangtze Craton). The results showed that the graphite inclusions whether protogenetic/syngenetic or epigenetic Raman shift in position of the G band and D band toward high frequency region and Show low ordered structures and defects. Raman shift of the protogentic/syngenetic graphite G band range from 1 591 to 1 600 cm-1, the shift of the G band of epigenetic graphite is wide rang from 1 575 to 1 588 cm-1, it is thought that forming pressure for diamond in Yuanjiang Basin(Yangtze Craton)is lower and its crystallization pressure have great varying range. We calculated the pressure are rang from 4.01 to 5.88 GPa according to Raman shift of the protogentic/syngenetic graphite G band range. It is consistent with what result of calculation in Raman shift of the olivine in Hunan diamonds, the D band rang from 1 350~1 368 cm-1 andthe G band and D band intensity ofprotogenetic/syngeneticgraphite inclusions of Hunan diamonds between 0.36 to 0.82, it indicatethat those area diamondswereformed depth is shallow and may be formed in a lithospheric mantle containing abundant eclogite. In these cases, the diamonds may have formed diamond-graphite boundary and diamond stability field. The graphite inclusion Raman shift of diamond is one of effective approach to explore the formation environment of the diamond primary area.

    Tools

    Get Citation

    Copy Citation Text

    MA Ying, WANG Qi, QIU Zhi-li, LU Tai-jin, LI Liu-fen, CHEN Hua, DENG Xiao-qin, BO Hao-nan. In-Situ Raman Spectroscopy Testing and Genesis of Graphite Inclusions in Alluvial Diamonds from Hunan[J]. Spectroscopy and Spectral Analysis, 2018, 38(6): 1753

    Download Citation

    EndNote(RIS)BibTexPlain Text
    Save article for my favorites
    Paper Information

    Received: Jun. 26, 2017

    Accepted: --

    Published Online: Jun. 29, 2018

    The Author Email:

    DOI:10.3964/j.issn.1000-0593(2018)06-1753-05

    Topics