This special issue is dedicated to Dr. Alessandro Guastoni, curator of the Museum of Mineralogy at University of Padova during the last 16 years. Sadly, Alessandro left us in December 2022 at the age of 56 due to an accident during an exploratory research trip for new mineral species. Alessandro was an expert in pegmatite mineralogy, his PhD thesis focused on LCT and NYF pegmatitic minerals in the Central Italian Alps. Alessandro published more than 50 papers in peer-reviewed international journals (and more than 200 articles in Italian and international non-peer review journals and books), he is the lead author of “Tutto Mineralogia”, a mineralogical reference book for students and mineral collectors and he was the director of the “Rivista Mineralogical Italiana” journal.

Alessandro was a bona fide mineral enthusiast and was extremely passionate about all aspects of this work, including research, teaching, and science dissemination. He was involved in hundreds of national and international collaborations and assumed many roles in the national scientific community in which he gained a reputation for helping students, colleagues, and friends no matter the circumstances. Recently, Alessandro started preparing the mineralogy section for the new Museum of Nature and Humankind at the University of Padova, the largest European university museum of its kind. The Museum opened in June 2023 and includes a commemorative mineralogy section entitled “The Alessandro Guastoni Mineralogical section”.