Interplay between the distribution of nitrogen and hydrogen and mineral inclusions in E-type diamonds from Yakutia, Siberian craton

Diamonds in nature are known to have formed by redox-assisted precipitation of carbon from oxidized fluids containing also hydrogen and nitrogen, both of which are hosted in the diamond lattice. Minerals entrapped during the growth of diamonds might have played a role in nitrogen and hydrogen incorporation and abundance although, so far, no evidence has been reported. We used synchrotron micro-FTIR mapping to investigate the interplay between the distribution of nitrogen and hydrogen and mineral inclusions (graphite, sulfide and garnet) in four eclogitic diamonds from the Yakutian kimberlite field, Siberian craton. Combined mapping of nitrogen and hydrogen-related infrared bands reveals heterogeneities near minerals. In particular, a marked absorbance of N- and H-related peaks observed in correspondence with sulfide inclusions supports their incorporation in the host mineral, while near graphite and garnet inclusions, only the H peak absorbance of peaks at 3107 cm ^− 1 , 1405 cm ^− 1, and 3236 cm ^− 1 increases. These zones can extend to tens of micrometers from the inclusion-diamond interfaces and provide insight into the potential control that entrapped minerals exert on the distribution and abundance of N and H in the diamond lattice during and after its formation at mantle depths.