Glass is very energy-expensive to manufacture. It softens around 1000 degrees centigrade and melts around 1500 degrees centigrade, which makes it incredibly exp

Glass is very energy-expensive to manufacture. It softens around 1000 degrees centigrade and melts around 1500 degrees centigrade, which makes it incredibly expensive to recycle into a product with a different geometry. For glass bottles at least, "recycling" consists of washing the bottle and shipping it back to the bottler. (Here in Korea, people use the empty bottles as ash trays, and occasionally a bottle with ash still in it is delivered to a consumer, making the news.)