Sand underpins everything from skyscrapers to smartphones. Sharp sand (as opposed to rounded desert sand) is the key ...

The ideal materials to use are decomposed or crushed granite, fine gravel, small pebbles, and silica sand. Another suitable material, often found at farm feed stores, is turkey or chicken grit.

But to make clear glass, a special sand called Silica Sand is used. This fine sand is needed because it's very pure, and does not contain any other unwanted chemicals. This special sand comes from ...