system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: 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.
gpt
Okay, so this is really cool. First, clear glass can't be made of just any sand, it needs to specifically be quartz sand, basically. Quartz, as you might know, actually is clear. However, if you look at quartz sand, it still would look a sort of pale tan color, like most sand. This, however, is precisely BECAUSE it is in tiny pieces. At the edges of clear objects, light often gets bent and bounced around to make the edges look white, especially if the surface isn't perfectly smooth (think of the edges of a frosted clear plastic straw, for example). Multiply that effect by super tiny size of sand grains and millions of little pieces, and even pretty clear sand doesn't look clear. But if you melt them all together and cool them in a way that doesn't allow for crystallization, and you get one, big, clear piece. That's glass! 

Please note that this is simplified a lot, but accurate to the basic concepts.