Abstract:The Brazilian diamond samples were analyzed by conventional gemological testing instruments combined with Fourier transform infrared spectrometers (FTIR), laser Raman spectroscopy, and Diamond ViewTM. The results revealed that the surface microforms of Brazilian diamonds are extremely diverse, featuring various growth mounds, trigonal, hexagonal, or irregular fusion pits, as well as plastic deformation slip lines. The Brazilian diamond samples are predominantly composed of the ⅠaAB type, accounting for over 90% of the total samples. It exhibits a nitrogen content ranging from 400×10-6~1 700×10-6 and a B core conversion rate between 15% and 66%. These findings indicate that Brazilian diamond samples are characterized by a high nitrogen content and a low to moderate degree of nitrogen aggregation. Raman spectroscopy analysis shows that there is residual compressive stress or poor crystallinity inside the sample. Diamond ViewTM luminescence images reveal blue and yellow-green fluorescence is popular in Brazilian ⅠaAB diamonds. Type ⅠaB diamonds exhibit blue fluorescence with green hues and an uneven blue fluorescence. The Type Ⅱa diamond samples exhibit dark orange and blue fluorescence.