Dear Colleagues: The 18th International Clay Conference (ICC 2025), organized under the auspices of the Association Internationale pour l’Etude des Argiles (AIPEA)will take place at Trinity College, Dublin, Ireland, from the 13th to the 18th of July 2025. [https://icc.aipea.org/sessions-list/](https://icc.aipea.org/sessions-list/ "https://icc.aipea.org/sessions-list/").  You are invited to participate with a scientific contribution as a poster or oral presentation, welcoming case studies and innovative research to the session: "From dioctahedral to trioctahedral smectites: Where volcanism meets weathering, sedimentation and diagenesis" organized by George E. Christidis, Manuel Pozo and Telma Musso  (<https://icc.aipea.org/sessions-list/icc-04>) Best wishes George