Crystal is in some ways similar to glass: both of them are obtained by a fusion process, during which glass is obtained thanks to the cooling of a mass of particular components that previously was brought to the liquid state. The substantial difference between these two materials is given by the presence of lead oxide, that allows the glass density, so the refractive index, to increase remarkably. In such a way the glass is approaching the optical properties of diamond: the light that hits it reflects more than glass, creating an effect of great brilliance, typical of lead glass. Around a goblet, a water jug, a piece of crystal, there is an entire world made up of people working for its skills: engravers, glass-blowers, grinders etc.: everyone places his own signature on the object while it takes a shape, fundamentally contributing to the final result, constructed with infinite patience, attention and precision.