Glass is made of sand, which is a kind of rock. But glass is transparent. We explore why! Glass is made of sand, which is a kind of rock. But glass is transparent, and rocks aren’t transparent. What’s ...

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their ...

Glass making dates back to ancient Mesopotamia, an astonishing 4,000 years ago. Known as “humankind’s most important material,” 1 glass is ubiquitous in our modern environment. It is used in the ...