Glass, the material

Glass is one of the oldest materials used by man. Born from the encounter of sand and fire, this shiny, transparent body has a viscous behavior, to which it owes its incomparable appearance and its blend of hardness and elasticity. We can't look at glass without talking about its structure and its many constituents, whose proportions determine its properties.

From glassblowing to industrial forming, glassmaking has undergone many technical evolutions. Over the last few centuries, float technology and advances in shaping methods have contributed to low-cost glass and its immense popularity.

From glazing and bottles to glass ceramics and tableware, glass is an inescapable part of modern life.

Nowadays, glass is used in most cutting-edge technologies, with applications in IT, energy, telephony and aeronautics. And in many fields, it's not about to be supplanted.

In the narrowest sense of the term, glass is a shiny, transparent body obtained by the simultaneous fusion of silica (sand, quartz, etc.) and an alkaline oxide or salt.

This definition is far from sufficient, and it's worth pointing out the viscous behavior of this material. To be precise, glass, which can be described as a frozen subcooled liquid, is a mineral product obtained by melting and solidification, without crystallization, i.e. during sufficiently rapid cooling. This non-crystalline solid material, which exhibits the vitreous transition phenomenon, is a perfect illustration of what is known as the vitreous state.

Unlike mineral solids, whose structure is rigorously ordered, glass is characterized by a disordered structure, similar to that of liquids, or at least without atomic order over long distances. In fact, as a direct product of the liquid, glass retains many of the liquid's properties. The characteristics of its atomic lattice give it, on a macroscopic scale, great homogeneity and total isotropy (uniform distribution in all three directions). It is transparent to radiation, with few free electrons to resonate. It can accept wide variations in chemical composition without the need for stoichiometry. In a way, it acts as a solvent for each of its constituents. Finally, from a mechanical standpoint, glass behaves like an ideal brittle solid at room temperature. It is perfectly elastic and appreciably hard. Unaffected by atmospheric agents, it retains its properties over time, justifying its use in the building industry.