EMU Notes in Mineralogy, Vol. 20 (2019), Chapter 3, 87–150 Glass and other vitreous materials through history Ivana ANGELINI1, Bernard GRATUZE2 and Gilberto ARTIOLI3 1Department of Cultural Heritage, Universita` di Padova, Piazza Capitaniato 7, 35139 Padova, Italy
[email protected] 2CNRS, Universite´ d’Orle´ans, IRAMAT-CEB, 3D rue de la Fe´rollerie, F-45071, Orle´ans Cedex 2, France
[email protected] 3Department of Geosciences and CIRCe Centre, Universita` di Padova, Via Gradenigo 6, 35131 Padova, Italy
[email protected] Early vitreous materials include homogeneous glass, glassy faience, faience and glazed stones. These materials evolved slowly into more specialized substances such as enamels, engobes, lustres, or even modern metallic glass. The nature and properties of vitreous materials are summarized briefly, with an eye to the historical evolution of glass production in the Mediterranean world. Focus is on the evolution of European, Egyptian, and Near East materials. Notes on Chinese and Indian glass are reported for comparison. The most common techniques of mineralogical and chemical characterization of vitreous materials are described, highlighting the information derived for the purposes of archaeometric analysis and conservation. 1. Introduction: chemistry, mineralogy and texture of vitreous materials Glass is a solid material that does not have long-range order in the atomic arrangement, as opposed to crystalline solids having ordered atomic configurations on a lattice (Doremus, 1994; Shelby, 2005). It has been shown experimentally (Huang et al., 2012) that amorphous solids can be described adequately by the model proposed by Zachariasen, the so-called random network theory (Zachariasen, 1932). Because of the contribution of configurational entropy, glass has a higher Gibbs free energy than a solid with the same composition.