Trinitite

Trinitite is the name given to deposits left behind after nulcear testing. It's composed of silica and quartz from sand sucked up into the centre of the explosion, where it fuses together to form a kind of man made pseudo-mineral.

A number of different types of Trinitite have been identified. Green is the most common form. Black contains iron from the tower structure. Red contains copper from the 'gadget' itself or from the communications cables that led away from the site. Both black and red specimens are extremely rare. Rounded pearls are also found which come from melted silica that returned to solid form before hitting the ground.