It was made my heating several minerals at high temperatures.EDIT: History has it some Arabs were cooking on sand, and noticed lumps of meted material in the ash after the fire cooled. The sodium...
Glass is made inside a volcano, as Obsidian, a black glassy material. Of much use in primitive society as a cutting implement. A lightning strike may also form a glassy object, rather uncommon, and...
you need sand, lime, and soda ash. You have to melt all this stuff together. You can't just like melt it in a microwave, though. It's done in like professional heating furnaces. When it dries it...