Micro- and nano-inclusions in a superdeep diamond from São Luiz, Brazil
- 117 Downloads
We report cloudy micro- and nano-inclusions in a superdeep diamond from São-Luiz, Brazil which contains inclusions of ferropericlase (Mg, Fe)O and former bridgmanite (Mg, Fe)SiO3 and ringwoodite (Mg, Fe)2SiO4. Field emission-SEM and TEM observations showed that the cloudy inclusions were composed of euhedral micro-inclusions with grain sizes ranging from tens nanometers to submicrometers. Infrared absorption spectra of the cloudy inclusions showed that water, carbonate, and silicates were not major components of these micro- and nano-inclusions and suggested that the main constituent of the inclusions was infrared-inactive. Some inclusions were suggested to contain material with lower atomic numbers than that of carbon. Mineral phase of nano- and micro-inclusions is unclear at present. Microbeam X-ray fluorescence analysis clarified that the micro-inclusions contained transition metals (Cr, Mn, Fe, Co, Ni, Cu, Zn) possibly as metallic or sulfide phases. The cloudy inclusions provide an important information on the growth environment of superdeep diamonds in the transition zone or the lower mantle.
Keywordssuperdeep diamond micro-inclusion nano-inclusion lower mantle
Unable to display preview. Download preview PDF.
- E. Fritch, T. Hainschwang, L. Massi, and B. Rondeau, “Hydrogen–related optical centers in natural diamond,” New Diamond Front. Carbon Technol. 17, 63–69 (2007).Google Scholar
- Y. Gohshi, S. Aoki, A. Iida, S. Hayakawa, and K. Sakurai, “SR microbeam X–ray analysis,” Photon Factory Activity Report 5, 130 (1987).Google Scholar
- B. Harte, J. W. Harris, M. T. Hutchison, G. R. Watt, and M. C. Wilding, “Lower mantle mineral associations in diamonds from Sao Luiz, Brazil,” in Mantle Petrology: Field Observations and High Pressure Experimentation: A Tribute to Francis R. (Joe) Boyd, Ed. by Y. Fei, C.M. Bertka, and B.O. Mysen, Geochem. Soc. Sp. Publ. 6, 125–153 (2010).Google Scholar
- J. Rudloff, F. E. Brenker, S. Schmitz, F. V. Kaminsky, and R. Wirth “TEM investigations of nanoinclusions in milky diamonds from Juina, a super deep source.” Goldschmidt 2015 Abstracts, p. 2710 (2015).Google Scholar