What is the name and formula of the compound commonly used in the manufacture of glass to increase the index of refraction?

The index of refraction is a dimensionless number that describes how light propagates through a medium. It is defined as the ratio of the speed of light in a vacuum to the speed of light in the medium. A higher index indicates that light travels slower in that medium, which can enhance optical properties such as clarity and brightness in materials like glass.

Glass is primarily made from silica (SiO2), but various additives are included to modify its properties. These additives can include alkali metals, alumina, and other compounds that influence characteristics such as durability, melting point, and optical clarity. Understanding the role of these additives is crucial for producing glass with specific refractive indices.

Borosilicate glass is a type of glass that includes boron trioxide (B2O3) as an additive, which significantly increases its resistance to thermal shock and enhances its refractive index. This type of glass is commonly used in laboratory glassware and high-quality optics due to its superior properties compared to standard soda-lime glass.