Biogenic Structure of Seashells: Mineralogical and Surface Properties of Flexopecten glaber (Linnaeus, 1758) Collected from Bandırma Bay, the Sea of Marmara

This study was conducted to determine the mineralogical structure and surface characteristics of marine shells belonging to the species Flexopecten glaber (Linnaeus, 1758). In the study, characterization was performed using PZC (point of zero charge), XRD (X-ray diffraction), SEM-EDS (Scanning Electron Microscopy – Energy Dispersive Spectroscopy), and FT-IR (Fourier Transform Infrared Spectroscopy) techniques. As a result of the PZC analysis, the zero point charge of the shell surface was determined to be at pH 8.33, indicating that the surface carries a positive charge below pH 8.33 and a negative charge above this value. This suggests that the shell surface may exhibit significant differences in electrostatic behavior in response to environmental pH changes. XRD analyses revealed that the crystal structure of the shells was predominantly showed as calcium carbonate (CaCO₃) form. EDS results showed that the shell composition contains 54.9% carbon, 7.5% calcium, and 6.1% nitrogen. Additionally, trace amounts of sodium (0.2%), magnesium (0.1%), and sulfur (0.1%) were detected. These data indicate that the shell structure is a complex biomaterial composed of both inorganic and organic components. The results provide important data for understanding the sensitivity of Flexopecten glaber shells to environmental factors and the responses of marine organisms to environmental changes. This study offers significant scientific contributions for understanding environmental adaptation mechanisms and the sustainable management of marine resources.