Brecce di Seravezza s.l. (Including Breccia medicea): A Treasure Stone in the Marble Heritage of the Alpi Apuane (Tuscany, Italy)

The Brecce di Seravezza s.l. (including Breccia medicea = Medici’s Breccia) represent a geological and commercial peculiarity in the heritage of the Alpi Apuane (Tuscany, Italy). The appearance of this ornamental stone varies, due to the size of the clasts and their colour, to the provenance from one quarry to another and within the same quarry depending on the stratigraphic level, giving rise to different typologies. In this contribution, samples coming from two historical quarries of the typical Stazzema area (Cava del Rondone c/o Pontestazzemese and Cava Grotte Bianche c/o Volegno) were studied. The Brecce of these two sections are stratigraphically interposed between the Marmi a Megalodontidi, at the bottom, and Marmi of Alpi Apuane, at the top. The “classical” feature of the Brecce di Seravezza s.l. used in art and architecture (consisting in a “disorganized” breccia with whitish to reddish marble and minor dolomitic marble pebbles to boulders in a reddish/violet, foliated carbonatic-phyllitic matrix) is recognizable only in some parts of the sections. Lithostratigraphicstructural, petrographic and microstructural observations in polarized light (PLM), mineralogical qualitative analyses with X-ray powder diffraction (XRPD), Scanning Electron Microscope Energy-Dispersive Spectroscopy (SEM-EDS) analyses allow us to identify the main features for 14 representative samples (8 from Cava del Rondone section and 6 from Cava Grotte Bianche section). Furthermore, the main uses of these materials in the cultural heritage context and the main decay phenomena observed in the outdoor and indoor areas will be presented.