The application of INAA to the geochemical analysis of single diamonds

Instrumental neutron activation analysis (INAA) has been applied to the analysis of 62 small (0.01-0.5 carat), single, inclusion-bearing and inclusion-free diamonds from South Africa, Brazil and Colorado. Up to 40 elements were detected at the ppb and ppt levels in individual diamonds of the eclogitic (basaltic affinity) and the peridotitic (ultramafic) paragenesis. The data obtained in this study can be used to distinguish between diamonds from the eclogitic and peridotitic parageneses and provides geochemical information on the environment in which diamonds crystallize. Further, the technique may prove to be useful in ''fingerprinting'' diamonds of different provenance areas.