Abstract The present study endeavors chemical and mineralogical characteristics in Meretrix casta (Bivalve) shells of the Yadayanthittu estuary, Southeast coast of India. In this estuary shell specimens were collected at 100m distance in the sampling stretch. The oxides, the elements and biominerals were measured with the aid of an integrated XRF and XRD instrument. The result of oxides demonstrates that the CaO content is in high percentages (54.47), which is common in organic shells. Apart from CaO, the other reported important oxides are Na2O, (0.697), SiO2, (0.241), Fe2O3, (0.116), MgO, (0.0661) and Al2O3, (0.0587). The elemental concentration shows that Ca with high level of 38.95 wt%. All other reported elements are only in lesser wt %, i.e. Na, (0.517), Si, (0.113) Sr, (0.156) Fe (0.0813), Sx (0.0266), Mg (0.0399) and Al (0.0311). The XRD analysis exhibits that the Meretrix casta shells of the Yadayanthittu estuary is formed by aragonite (98%) and selwynite (2%) biominerals.
Keywords Yadayanthittu estuary, Meretrix casta, XRF and XRD, oxides, elements, biominerals