Medieval Glassworks in the City of Ferrara (North Eastern Italy): The Case Study of Piazza Municipale

Abstract

Compositional and structural characterization was carried out on transparent glass fragments found in a brick rubbish pit discovered in basal floor of the ducal palace of Ferrara, during the excavation of Piazza Municipale. This study aims to identify raw materials and glass-working techniques through X-Ray Fluorescence (XRF) quantitative chemical analyses and semi-quantitative Scanning Electron Microscopy (SEM) observations. The studied fragments were produced using siliceous-lime sands with natron as flux, and allowed us to better understand the production technologies in a historical period of great innovation for European glass art. The numerous findings of glass fragments discovered in brick underground cellars built for the specific purpose of household rubbish of wealthy complexes in Ferrara testify a consolidated system of separate discharge of solid waste into underground containers, which were closed and sealed once filled. The high volume of the finds indicates the absence of recycling of accumulated materials due to the well-being of the city. Compositional analysis confirmed the local production of glass shops in Ferrara during the late Middle Ages, characterized by differences with the glasses of the nearby city of Venice. Morphological analyses also defined the nature and relative abundance of the products, exploring the types and compositions of the Ferrara glass art.

Geochemical and Mineralogical Characterization of Construction Materials from Historical Buildings of Ferrara (Italy)

“…Santa Maria delle Grazie San Andrea After that, 0.5 g of the powder for each sample was prepared by pressing a tablet on boric acid support for the XRF analysis. The chemical composition of the collected samples was determined by X-ray fluorescence (XRF) with a wavelength dispersion spectrometer ARL Advant-XP (Thermo Fisher Scientific, Waltham, MA, USA) [30] and consisted of an X-ray tube with a Mo target and an SSD Peltier-cooled detector (10 mm 2 active area and resolution of <155 eV at 10 kcps) [31]. The maximum voltage and current of 50 kV and 1500 µA, respectively, were used to excite the secondary fluorescence X-rays.…”

“…The mineralogical characterization of the samples, previously ground using water and then dried and powdered within an agate mill, was carried out by X-ray powder diffraction (XRPD) by means of a PW1860/00 diffractometer (Philips, Eindhoven, The Netherlands) [36], with a graphite filtered and a Cu Kα radiation (1.54 Å) in a 2θ angular range 5-75 • , with a 5 s/step (0.02 • 2θ). Diffraction patterns were collected in the 2θ angular range 3-50 • , with a 5 s/step (0.02 2θ) [30,37].…”

“…The high value of SiO 2 probably depends on the quantity of fusing agent added to the bricks. However, the low level of TiO 2 impurity could be an indicator that a pure SiO 2 agent was probably used [30].…”

Natural Stones Used in the Orsi-Marconi Palace Façade (Bologna): A Petro-Mineralogical Characterization

“…In addition, Optical Transmitted Light Polarized Microscopy (OTLPM) of thin sections is one of the fundamental and widely used techniques for the study of minerals and rocks. In this specific work, OTLPM provided information about the presence of fractures, which is useful data to identify its formation environment and give a name to the studied rock [33,34].…”

“…Mineralogical characterization of the samples, previously grinded, using water, then dried and powdered within an agate mill was carried out by X-ray diffraction (XRD) by means of a PW1860/00 diffractometer (Philips), with a graphite filtered and a Cu Kα radiation (1.54 Å) in a 2θ angular range 5-75 • , with a 5 s/step (0.02 • 2θ). Diffraction patterns were collected in the 2θ angular range 3-50 • , with a 5 s/step (0.02 2θ) [34,40].…”