eli5: Why does sand which is a bunch of tiny rocks, turn into glass, but we can’t turn big rocks into glass?


I’m very tired. Please help me understand this.

In: Other

It has to do with the composition of the sand (silica). Rocks tend to contain mainly quartz and feldspar.

You won’t be turning just any sand into glass. You certainly won’t be turning it into *clear* glass.

The ‘tiny rocks’ that can be made into glass are already transparent. Melting them together gets rid of voids and makes the bulk substance transparent.

Check out “How to Make Everything” on YouTube and search for “glass”. There are a few videos on the process of glass making, problems trying to make glass from scratch, etc.

What do you think sand is? It’s the result of those big rocks being crushed and abraded and sorted until what you have is rather pure quartz, because it’s much harder than the other minerals in the rock. We can do the same thing industrially, but there’s little point when there’s still plenty of glass-grade quartz left. Not to mention the huge amounts of waste that has no particularly productive use given the bulk.

both are possible but only the former is economically feasible i.e. we CAN turn big rocks into glass.