Trinity is the name of the first nuclear device test, a detonation in the New Mexico desert at 05:29 MWT, 16 July 1945. The temperature of approximately 1470 degrees C fused the desert sand with radioactive debris, forming a 400-yard radius area “glazed with a green, glass-like substance where the sand had melted and solidified again’’ (Storms, 1965). This glassy formation, named Trinitite, is composed of two distinct types of glass: one formed from the feldspar and clay, and another from quartz that fused directly into silica glass. Calcite, hornblende, and augite are also present. Green is the most common colour.

Much of the Trinitite was removed and buried by the Atomic Energy Commission in 1952, and although the test site is now a National Historic Landmark on the National Register of Historic Places, people will take things; apparently so much trinitite wandered off the premises while it was still being sold to mineral collectors that it is considered unlikely that the available supply is fake.