why is glass transparent when all the materials used in it are opaque ?

Answer 1

It depends on the crystalline structure obtained. ~

Answer 2

This little trick is solved through crystalline bonding, or the way the molecules align to form the glass. The molecules that make things like sand opaque, usually a low grade silicate, are usually burned off in the high heat and pressure used to make glass, leaving only the elements necessary for the glass, which when they arrange themselves into a crystal structure at such high temperatures, cool down to be clear.

Answer 3

Well cheap glass is made of out sand. Sand is usually quartz which is usually a transparent or translucent mineral. It just doesn't look that way at first but if you look closely at some sand grains you will see they are at least translucent. Also, glass making techniques ensure that the product is clear.

Answer 4

When you melt a substance and cool it suddenly, you get glass.

When you do the same with carbon, you get diamond.