Trinitite is a glassy substance formed from the intense heat of the first atomic bomb test, known as the Trinity Test, which took place on July 16, 1945, in New Mexico. When the bomb exploded, the extreme temperatures melted the surrounding sand, creating a greenish glass that solidified as it cooled. This material is often found in small, irregular pieces and can vary in color from green to brown. Trinitite is considered a significant artifact of nuclear history and is sometimes collected by enthusiasts, although its sale is regulated due to its historical importance.