To make glasses stronger and more durable, stabilizers are added. The most common stabilizer is lime (CaO), but others are magnesia (MgO), baria (BaO), and litharge (PbO). The most common glass, made in largest amounts by both ancient and modern glassmakers, is based on silica as the glass former, soda as the flux, and lime as the stabilizer. It is the glass used to make windows, bottles, jars, and lightbulbs.
Colored Glass. The natural glasses used by the ancients were all dark in color, usually ranging from olive green or brown to jet black. The color was