title: [Micro-FTIR mapping tracer for the heterogeneity growth of nitrogen impurities in natural diamond from three localities in China].
abstract: The geographic locality determination of diamonds is of great significance in understanding the mantle evolution, restricting the illegal trade of conflict diamonds, etc. In the present article, the in-situ analysis of micro-FTIR surface scan technique was first applied to analyze 14 IaAB natural diamond specimens from China's three commercial localities. According to the FTIR spectra of diamonds, the nitrogen contents were calculated (1616 data points of FTIR) and used for mapping tracer. Th results showed that the nitrogen contents and its aggregation often varied in the process of diamond growth, and the nitrogen contents in initial nucleation stage could be higher or lower than in other stages. It is not an unidirectional variation for nitroge contents in different growth stages, indicating that the carbon and nitrogen had a complex exchange with mantle fluid during the diamond's crystallization course. It was regionally different between the diamonds from the three localities in the frequency distribution of nitrogen contents and NB%/N(T). Micro-FTIR mapping is more intuitive than the method of selecting discontinuous points, and it can trace the heterogeneous growth of nitrogen impurities in natural diamonds consecutively.
authors.affiliation: Department of Earth Science, Sun Yat-sen University, Guangzhou 510275, China. sunyuan728@yahoo.com.cn
authors.forename: Yuan
authors.initials: Y
authors.lastname: Sun
authors.forename: Zhi-li
authors.initials: ZL
authors.lastname: Qiu
authors.forename: Tai-jin
authors.initials: TJ
authors.lastname: Lu
authors.forename: Hua
authors.initials: H
authors.lastname: Chen
authors.forename: Bing-hui
authors.initials: BH
authors.lastname: Chen
authors.forename: Shu-yi
authors.initials: SY
authors.lastname: Peng
authors.forename: Ran
authors.initials: R
authors.lastname: Wei
authors.forename: Liu-fen
authors.initials: LF
authors.lastname: Li