Lead glass, commonly called crystal, is a variety of glass in which lead replaces the calcium content of a typical potash glass. Lead glass contains typically 18–40% lead(II) oxide (PbO), while modern lead crystal, historically also known as flint glass due to the original silica source, contains a minimum of 24% PbO. Lead glass is often desirable for a variety of uses due to its clarity. In marketing terms it is often called crystal glass.
Cut glass wine glass made of lead glass
Fluoroscopy room with control space separated by lead shielding glass
Lead crystal beads
Glass is a non-crystalline solid that is often transparent, brittle and chemically inert. It has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics.
A glass building facade
A piece of volcanic obsidian glass
Moldavite, a natural glass formed by meteorite impact, from Besednice, Bohemia
Tube fulgurites