[wreckdropibex]

You would think sand is plentiful, but eg https://www.bbc.com/future/article/20191108-why-the-world-is....

[Ekaros]

I have been wondering about this in context of glass... With concrete and such applications you cannot have too smoot sand, but is it same for glass? As you are going to melt it anyway, it shouldn't matter if it is not usable in concrete...