What exactly is glass?


How does glass become transparent if it’s made of sand. My lil brainy can’t make sense of small rocks (my knowledge of sand) becoming transparent by any process like melting or pressure.

In: Chemistry

You melt down the sand(1700-1800C) and then you cool it down.It undergoes a transformation with different inner structure,but the sand is never quite solid,doesnt matter how much you cool it(it is a frozen liquid referred as amorphous solid)

Think of it like ice cubes. Most ice cubes you see aren’t clear, they’re white. This has to do with impurities and bubbles while solidifying. But there is a way to make completely clear ice cubes (many companies are in business to provide clear ice), and it’s done using a specific process. In this process, when water crystalizes, the water crystals form in such a way that light doesn’t diffuse while passing through. The silica crystals that are made into clear glass do the same. the light passes all in the same direction (I don’t say pass through, because in both water and glass, the light gets refracted, but all in the same direction).

So, the sand that glass is made of is quartz sand. You can have basalt sand, it just doesn’t look like what you’re used to. Quartz, in its purest form, is clear. Glass is melted and resolidified quartz.

If you’re wondering why glass is clear but not other materials, it’s because glass is mostly silicon dioxide, the same thing as quartz. In quartz it’s a crystal, a perfect lattice of interconnected molecules. In glass they’re randomly arranged and frozen into place.

It’s clear to visible light because none of its atoms have electrons whose energy matches the wavelengths of visible light – if they matched, an electron could absorb that photon and store it as energy – so they just pass on through. However, it DOES match for infrared, so if you tried looking through glass with a thermal camera it would look solid.

This is also the cause of the greenhouse effect – visible light goes through glass, hits something that CAN absorb it, it’s re-emitted as thermal light, which is BLOCKED by glass, so the energy stays trapped and keeps warming up like a bucket filling with water faster than it drains.

Thanks for all answers! My confusion is cured! Love you guys