While many minerals can be melted and cooled to form glass, the most common mineral used to make glass is quartz.

Here's why:

* Silica: Quartz is primarily composed of silica (SiO2), which is the main component of most glass.

* Melting Point: Quartz has a relatively high melting point, making it suitable for glass production.

* Transparency: Silica glass is transparent, which is a desirable property for many glass applications.

However, it's important to note that pure silica glass is very difficult to work with. It has a high melting point and tends to crystallize quickly. So, other substances are often added to silica to modify its properties, such as:

* Soda ash (sodium carbonate): This lowers the melting point of silica and makes it easier to work with.

* Lime (calcium oxide): This improves the chemical durability and stability of the glass.

So, while quartz is the primary mineral, the process of making glass involves a combination of minerals and other ingredients.