FTIR CHARACTERS OF DIAMOND FROM HUNAN PROVINCE

The diamond from Yuan River, Hunan Province, an important place of diamond production, is of multiple geneses and sources. The FTIR spectra of 120 rough diamonds and 10 slab diamonds show that most of the diamonds belong to types of IaA and IaAB and few to typical IaB, and that the proportion of types of Ib and IIa is higher slightly than that of other diamonds in other areas. 70% of diamonds contain nitrogen lower than atomic 100×10 ^-6. The pattern of nitrogen aggregation changes from Center C to Center A and from Center A to Center B from the core to the rim in diamond. The content of nitrogen and hydrogen in diamond changes unexpectedly from the core to the rim. The changes reflects that the environment in which diamond formed is often variable.