使玻璃和陶瓷更坚固、更耐用、使用寿命更长，并能抵抗热膨胀。

Lithia is lithium oxide released from either lithium carbonate or spodumene. Adding lithia increases glass melt rate, and lowers the viscosity and the melt temperature, resulting in:

• Process productivity increased by a higher output
• Energy savings and molding benefits
• Improved mechanical and optical properties
• Enhanced strength, durability and brilliance of the glass

Common applications include optical products, container glass, flat glass, pharmaceutical glass, specialty glass and fiberglass. Lithia is also used in glass-ceramic cooktops where no thermal expansion and thermal resistance is essential.

Other lithium salts such as chloride, fluoride, phosphate, silicate or sulfate are used in specific applications.

Various forms of cesium (cesium nitrate, cesium carbonate and cesium bicarbonate) are used to modify the refractive index of optical glass and to resist corrosion or breakage for glass surfaces. Rubidium carbonate is applied in glass lenses used in night vision devices.