Glass is a hard brittle substance, typically transparent or translucent, made by fusing sand with soda, lime and sometimes other ingredients and cooling rapidly. Libyan desert glass or great sand sea glass is a substance found in areas in the Libyan Desert. Fragments of desert glass can be found over large areas, up to tens of kilometers. The Libyan desert glass has been dated as having formed about 26 million years ago. It was knapped and used to make tools during the Pleistocene. Today’s glass is used to make windows, drinking containers and many other articles.