This is real “ivory black” made from real ivory. Often pigments commercialized as “ivory black” are made from ordinary animal bones. It is the least pure form of carbon black, containing a high percentage of calcium phosphate.
DOWNLOAD paper: “Pigments Checker version 3.0, a handy set for conservation scientists: A free online Raman spectra database”
DOWNLOAD paper: “FORS spectral database of historical pigments in different binders”