DANAT research detailing the chemistry of more than 1000 samples from different molluscs was recently published. Samples from freshwater sources were found to contain more manganese and barium than their saltwater counterparts. On the other hand, samples from saltwater sources contained more sodium, magnesium and strontium than from freshwater sources. Some elements were found to differ from one sample to another, depending the mollusc where they were found. Samples from Pinctada radiata were found to contain less magnesium than the other samples from saltwater sources. Samples from Pinctada maxima contained higher manganese and from Pinctada imbricata higher barium than other studied samples from saltwater sources. These observations give valuable indicators towards the mollusc where the pearl was initially grown