During the eighteenth century, scientific literature devoted to the earth sciences documented a significant increase in the study of the composition and formation of mountains and above all their stratigraphical sequence. The diverse and widely ranging philosophical theories of the late seventeenth century on the origin of Earth were gradually replaced by new concepts based on field research on both a local and regional scale. This new approach analyzed the lithology and the fossil content of the rocks, the geomorphology of the area, and in some cases helped to determine the chronological sequence of mountain formation. Nicolaus Steno's idea of superimposition of strata (1667–1669) was followed by most of the late eighteenth-century scholars in earth sciences, who developed subdivisions of mountains from the point of view of their formation and also included a classification of the rocks. These subdivisions supported the idea of relative chronology of the formation sequence of the studied strata: the most recent or the most ancient formation could be deduced from its position in the sequence as well as from its external lithological features. In this context, the role of scientific terminology, which was gradually established in eighteenth-century geological science, became very important: the terms “primary” (or “primitive”), “secondary,” and “tertiary” were used for indicating the categories of mountains as well as for stratigraphic units. In the second half of the eighteenth century, the work of Giovanni Arduino contributed decisively to the development of basic lithostratigraphic “classification” of rocks and mountain building. His lithological studies, a result of twenty years of fieldwork in the mountains and hills of the Venetian and Tuscan regions, were also supported by a specialized knowledge of mining. The new “classification” into four basic units called “ordini” (1760) was based only on lithology (without using paleontological indicators) and included different rock types, which formed three kinds of mountains and one kind of plain, in a regular chronological order: “primary” (underlain by “primeval” schist considered by Arduino to be the oldest rock type), “secondary,” and “tertiary”; the “fourth” and younger chronolithological unit included only alluvial deposits. Arduino's system is still regarded by the geological world as being one of the starting points for modern stratigraphy.

Abstract The paper presents an overview of the principal stone materials used in the historical architecture of Tuscany, a region of central Italy characterized by a great variety of landscapes. The large number of these materials reflects the complex geology of the region, where each village and town has a unique identity conferred by the architecture and typical colours of the construction materials. The urban areas that have developed in the foothills of the Apennines are, characterized by the use of sandstone, while the towns and villages of central-southern Tuscany are generally more heterogeneous, with an abundant use of bricks and travertine. The information presented is focused on the use of the stone materials during the different epochs, their geopetrographical characteristics and their most common durability problems.

A brief history of the nature, use and technology of binders in ancient constructions and buildings is outlined, including the apparent chronological discontinuities related to technological developments. The skilled and clever use of mineral resources is at the base of the technical achievements related to architectural activities, from simple adobe to high-performance modern concrete. It is argued that among pre-industrial binders the Roman pozzolanic mortars were highly optimized materials, skillfully prepared and very durable. Their innovative use in architecture is one of the keys of the successful expansion of the Roman Empire. The role of mineralogy and mineral reactions is emphasized in terms of: (1) the preparation and manufacturing of the binding materials; (2) the hardening process and the development of the physical properties of the binder; and (3) the archaeometric reconstruction of the ancient materials.