Trinitite, also known as Atomsite or Alamogordo Glass, is a historic glass formed during the Trinity test in New Mexico, USA, on 16 July 1945. This was the world’s first nuclear detonation, carried out near Alamogordo as part of the Manhattan Project. The extreme heat of the explosion melted desert sand and surface material into glass, creating the distinctive material now known as Trinitite. Although it is not a meteorite, Tektite, or natural Impactite, it is often collected alongside high-energy glasses because of the extreme conditions under which it formed. The Smithsonian describes Trinitite as the glassy residue left after the Trinity nuclear bomb test.

Trinitite is most commonly pale green to grey-green, though colour and texture can vary depending on composition and formation conditions. Specimens often have a glassy upper surface and a rougher underside where molten material fused with the ground. Some pieces contain bubbles, flow structures, or small inclusions from the surrounding environment. It is primarily formed from melted desert sand and related surface material, giving it a distinctive texture that differs from both volcanic Obsidian and meteorite impact glass.

Studying Trinitite provides insight into extreme heat, rapid melting, and glass formation under one of the most historically significant artificial events of the 20th century. Its importance lies not in extraterrestrial origin, but in its direct connection to the beginning of the atomic age. For collectors, Trinitite offers a rare crossover between geology, history, science, and high-energy glass formation. Each specimen represents a physical remnant of the Trinity test, preserved as glass from a clearly documented moment in modern history.