Glass structure created by a deep–sea sponge. Photo © Joanna Aizenberg
We usually approach glass from an artistic standpoint around here, but I found a couple of interesting scientific articles about glass.
The first article takes a look at glass as "a familiar substance that nonetheless retains some elusive scientific mysteries". Of particular interest are the comments that "glasses can be formed from any substance", and that cosmologists have described the early universe as a glass.
According to this article about a deep sea sponge, it seems that humans aren't the only glass makers out there. The Venus' Flower Basket builds amazing glass structures using techniques similar to those found in engineering but at a microscopic scale.