Glass is made from a mixture of minerals melted together at a very high temperature. Silicon dioxide is the base of the glass, which is also the main component found in sand. So glass is essentially liquid sand.
To make glass, sand is heated until it becomes a liquid. After the molten sand cools down, it doesn’t revert to its original state. It goes through an entire transformation, which alters its inner structure. Even once the sand is cooled it’s still not a solid or a liquid, it’s both. Glass is referred to an amorphous solid—a cross between a liquid and solid.
For commercial glass that you see in ordinary windows or PYREX cookware, recycled glass is mixed with sand, limestone, soda ash, and heated in a furnace.
Once the sand is melted down, it can be poured into different molds to make glasses, jars, bottles, and other containers. To make windows, the melted sand is dispensed over molten tin for a completely flat shape.
In nature, when lightning strikes sand a vitrification of quartz—or transformation—turns the sand into glass. You’re not very likely to find chunks of glass after a storm since sand has an incredibly high melting point of 1700 degrees Celsius.
Glassblowers use a gob of molten glass wrapped on a pipe to create beautiful and delicate pieces of art. The tube is slowly rotated while air is blown through, causing a balloon to form at the end. This balloon can be shaped into amazing pieces with skilled blowing and turn.
Glassmakers add different metals and chemicals to alter the ordinary glass. Adding chromium and iron gives the glass a green tint that you frequently see in beer bottles. For a fine crystal glass that’s easy to cut, lead is added to the mixture.