What is another word for natural glass?
Pronunciation: [nˈat͡ʃəɹə͡l ɡlˈas] (IPA) 
Natural glass is an intriguing substance created by natural processes. Also referred to as fossilized or petrified glass, it forms when substances such as sand or ash are heated to high temperatures and then quickly cooled or subjected to other intense pressures. Alternative words for natural glass include obsidian, which is a black or dark brown volcanic glass; tektite, formed from the impact of meteorites on the earth's surface; and fulgurite, created when lightning strikes the ground. Each of these types of natural glass has unique characteristics that make them fascinating to geologists, archaeologists, and collectors alike.
