The “Quattro Evangelisti” pegmatitic blocks of the Museo La Specola: a restoration and re-exhibition project_Congresso congiunto SIMP-SGI 2025 - Geosciences and the Challenges of the 21st Century

Elba Island occupies a prominent place in the history of world mineralogy also for the extraordinary richness and complexity of its granitic pegmatites (Pratesi & Bonazzi, 2012). One of the most famous and iconic finds are the “Four Evangelists”, four large portions of pegmatitic geodes rich in crystallizations. They come from the site of Masso di Fonte del Prete, southeast of San Piero in Campo, later called Masso Foresi, in honor of Raffaello Foresi (1820-1876), who directed the extraction campaigns of 1872, as reported by Roster (Roster, 1876; Pezzotta, 2021). These blocks are enormous fragments of large miarolitic cavities, lined with crystals, formed inside the pegmatitic bodies during the last phases of their cooling. The paragenesis is typical of pegmatites with the presence of tourmaline (Elbaite), pink beryl, quartz, orthoclase, pollucite, petalite, lepidolite and zeolites (heulandite, chabasite, natrolite, stilbite and crookeite). Taking advantage of the transfer of the litho-mineralogical collection to the “La Specola” Museum, the Museum System planned their display in the new exhibition center in Via La Pira, annexed to the University Museum of Geology and Paleontology. In this context, it was deemed appropriate to carry out a thorough cleaning and consolidation of the finds, carried out at the specialized laboratories of the MCP company in Pioltello.