Board Thread:Suggestions forum/@comment-25124648-20160124131503/@comment-26172435-20160124134425

I second these! This would nicely add to other thoughts on more primitive construction materials for low value structures and/or primitive cultures, as vented here. Maybe you can combine these thoughts to also account for the abundance of Jungle Mud?

And indeed, production of glass requires a lot of energy, so it's certainly justifiable that this proposal results in doubling of the energy cost to create glass.