Abstract: A method for separating diamonds from associated gangue in a diamondiferous material. The method comprises the steps of mixing the diamondiferous material with water to form a slurry and passing the slurry through laser radiation of known wavelength in the infra red part of the electromagnetic spectrum to cause Raman spectral scattering of the radiation from the slurry. The scattered radiation is collected and filtered to isolate diamond-relevant radiation and the filtered radiation is analyzed to determine whether it is indicative of the presence of diamond. Finally, on the basis of such analysis, high diamond content slurry is separated from low diamond content slurry.