NAME: Vicenza Stone
GEOGRAPHIC DISTRIBUTION: Monti Berici
MAIN ACTIVE MINES: open mines and tunnels
GEOLOGIC FORMATION AND AGE: Tertiary Period or Cainozoic Era, Eocene middle period. This period is started 55 million years ago and is lasted 20 million years.
MINERALOGICAL COMPOSITION: clayey limestones lightly.
MACROSCOPIC ASPECT: gross limestone, with varied structure, formed by clastic material and by fossil remains, in particular by thin beddings of clayey materials (morillonites) and by fossils, mostly nummulites (fossils protozoans of the tertiary period, with calcerous shell with the form of a coin). It has a variable colours, from white to straw-coloured yellow.
PETROFRAPHIC DEFINITION: organogenic limestone.
CHEMICAL COMPOSITION: calcium carbonate (CaCO3), about 80%, not negligible percentages of silicon oxide, aluminium oxide and iron oxide. It is a -biomicrite- that is formed by microcrystalline calcium carbonate, of biologocal origin.
PHYSICAL AND MECHANICAL FEATURES: the burden of compression break is quite low (320 Kg/m2). The weight of every unity of volume is 2100 Kg/m3. It is a -geliva- rock.
POSSIBLE ALTERATIONS: on the surface the rock undergos a progressiva hardening due to the partial cementation of the pores.
WORKABILITY: it is very good workable, prevalently with the hammer and the bit of various dimensions. It is possible to saw it only when it has just been extracted, when there is up to "the water of mine".
USE: there are witnesses about the use of this stone till the roman period, at least in the zone around Vicenza. Only since Middle Ages there is its systematic utilization in the building, in the ornamentation and in the sculpture. It was a big diffusion since half of the XIV century until the first decades of the XVI century, at first at Vicenza and then at Padova. This was supported by the facility of the river transports throught the canal Bisatto that touched Ponte di Nanto, where there was and there is yet the mine for the extraction. It was used by the major sculptors and architects of Renaissance and of all the '600, from Palladio to Falconetto, from Sanmicheli to Sansovino. It was used in Venezia and in the Venetian hinterland, became less usual in the Veronese area. Because of the excellent workability it was very used in the creation of the armorial bearings and of other sculptural works and of the architectural parts as coverings, windowsills, jambs, frames of eaves and dripped, less for elements of forniture of gardens (so it uses more the tender stones of Vicenza, as for example in the statues of Prato della Valla and at Villa Pisani in Stra). It is exemolar the realization, in Padova, of the sixteenth century Loggia and Oden Cornaro, projected by Falconetto. After the half of '700, consistently to the neoclassic taste, it was preferred to the Nanto's stone, always lass used, the stone of Castrozza and in general the tender stone of Vicenza, today very used in Italy and at abroad for its versatility.