Abstract:

Traditionally, Earth Sciences teaching has relied on hand specimens as a fundamental tool for the recognition of geological elements and the comprehension of geological processes. Through direct observation of morphology, texture, and spatial relationships, students develop key competences in mineralogy, petrology, sedimentology, paleontology, and structural geology. However, collections are typically restricted to specific institutional settings, and specimens are often fragile or unique, which limits access and hinders the development of skills, such as identification, differentiation, and spatial reasoning. In this context, the digitalization of geological hand specimens represents a strategic opportunity to enhance learning processes, in line with current European priorities for digital education and innovation.

This contribution presents the ongoing digitalization of hand specimen collections from the Faculty of Earth Sciences (University of Barcelona), aimed at developing an educational resource for undergraduate teaching. Building on the methodology developed within the GEODIGIT project (Digital Transition in Geology: New Challenges from Field and Laboratory Data, TED2021-130602B-I00), and funded by teaching innovation projects (2024DIG-UB/006 and 2024PEDC-CCT/001), the initiative focuses on generating high-quality, scientifically rigorous 3D models from hand samples using photogrammetry. The workflow involves the acquisition of approximately 150 high-resolution photographs per sample, using an automated rotating platform synchronized with the camera. This ensures full geometric coverage and accurate color representation. The images are processed with specialized software to generate detailed 3D meshes and textures suitable for interactive visualization and integration into virtual learning environments. To date, more than 100 specimens have been digitized, including sedimentary, metamorphic, and igneous rocks, as well as fossils, ichnofossils, and sedimentary and tectonic structures. The models are hosted on open-access platforms and integrated into structured digital learning environments, enabling students to explore samples in detail anytime and anywhere.

From a pedagogical perspective, this resource promotes autonomous and inquiry-based learning and significantly enhance spatial reasoning skills. They also support active learning methodologies, including the flipped classroom, collaborative learning and problem-based learning. Furthermore, it facilitates hybrid or fully online teaching without compromising scientific rigor. However, some limitations must be acknowledged: transparent minerals remain challenging for photogrammetry, digital models cannot fully replicate the tactile experience of physical samples, and their effectiveness depends on model quality and curricular integration.

Beyond their current application, these resources provide a foundation for future developments in immersive learning environments, including virtual and augmented reality (teaching innovation project 2025PID-UB/015). Such approaches have the potential to further enhance student engagement by simulating field and laboratory experiences in accessible and scalable ways. Ultimately, the digitalization of geological collections represents a transferable and scalable model for the modernization of geoscience education, showcasing photogrammetry-based digitalization as a key strategy in the ongoing digital transformation in higher education.

Keywords:

3D digital models, hand samples, photogrametry, Geoscience Education.