Micro-inclusion-bearing coated diamonds from DRC

High-density fluid (HDF) micro-inclusions commonly found in fibrous diamonds offer a unique opportunity to explore the metasomatic events in the lithospheric mantle, during which the micro-inclusions and their host diamonds formed. It has been suggested that saline and silicic HDFs are immiscible due to the absence of intermediate compositions between these two endmembers. However, SiO2 and Cl-rich HDFs with compositions along the saline–silicic series were identified precisely at the diamond core–coat boundaries of coated diamonds from the Democratic Republic of the Congo (DRC). This dataset includes Fourier-transform infrared (FTIR), Raman, energy dispersive spectrometer (EDS), and laser ablation ICP–MS results of four coated diamonds from DRC, which reflect impurity features in different parts of diamonds, mineral macro-inclusion characteristics in the diamond core, and major and trace-element compositions and volatile content of micro-inclusions in the coat, providing new insights into mantle fluid evolution and revealing connections between diamond crystallization and fluid composition.