A dual approach to enhance the Targioni Tozzetti collection, a little-known mineralogical heritage: digital and analytical methods

After approximately 20 years since the project that digitized 4500 documents and estimated 2687 surviving specimens (Cipriani & Scarpellini, 2007), the litho-mineralogical collection of Giovanni Targioni Tozzetti (1712-1798) has once again become the subject of study. The collection is not solely composed of what we would consider minerals today, but it illustrates lithic materials in various manifestations. The collection follows the Linnaean logic that distinguishes nature among Animal, Vegetable and Mineral (Lapideum) Kingdom, placing itself in the latter. Giovanni not only gathers minerals and rocks, which constitute the most abundant specimens, but also shells and fossils. Furthermore, embodying the spirit of the experimental scientist in service of the nation, he collects samples during his territorial research aimed at discovering raw materials useful for the technological development of the Grand Duchy of Tuscany and provides information on origins, suppliers, and uses of different materials. The samples are document of the exploitation of ore deposits, lithic samples for construction, along with objects that testify the use of different materials (e.g., an armed magnet, made of magnetite), etc. Moreover, although the concept of a collection as a gathering for wonder and aesthetic contemplation had been surpassed, the separation between scientific and artistic value was not yet fully accomplished, hence there are also valuable artifacts such as worked stones or a lithic head of Etruscan manufacture. To preserve, enhance, and transmit to future generations the values and the data contained in this 18th century document of scientific and technological relevance, a dual approach has been taken. Firstly, 287 artifacts were inventoried (~11% of the total), among which 154 were catalogued following ICCD criteria. Consequently, 109 BNM (Beni Naturalistici-Mineralogia), 39 BNPE (Beni Naturalistici– Petrologia), 1 BNZ (Beni Naturalistici–Zoologia), and 5 PST (Patrimonio scientifico e tecnologico) cards were produced, accompanied by high-resolution images. The project is part of the Tuscany Region’s program which has led to the creation of an online portal dedicated to the digital fruition of Tuscan heritage. Simultaneously, an analytical campaign aimed at the correct mineralogical attribution of various specimens and a survey of their places of origin is underway. Specifically, 67 gems, both rough and cut, were analysed with optical microscope and μ-Raman to identify their mineral species (Fabrizi et al., 2023). In addition, 8 massive samples containing metallic minerals catalogued as “Stannum” and 11 as “Plumbum” underwent to optical microscope and SEM-EDS analysis for identifying the paragenesis and compare it with the deposits of origin. Some noteworthy pieces have been identified during these studies and exhibited for the first time in the new exhibition dedicated to mineralogy, at the “La Specola” museum of the University of Florence Museum System.