A beautiful, large specimen that looks great from every angle. It can be a beautiful piece of any collection. Libyan desert glass or Great Sand Sea glass is an impactite, made mostly of lechatelierite, [1] found in areas in the eastern Sahara, in the deserts of eastern Libya and western Egypt. Fragments of desert glass can be found over areas of tens of square kilometers. Like obsidian, it was knapped and used to make tools during the Pleistocene.