Space impact and Tutankhamun gem

An article from the BBC reports that the one of the gems in a necklace of Tutankhamun may have come about as a result of a space impact. The gem was found upon analysis to be made from an usual green glass, which may have been produced when a comet hit Egypt. Thinking of the Tunguska strike,
Wasson wondered if a similar aerial burst could have produced enough heat to turn the ground to glass in the Egyptian desert.
The first atomic bomb detonation, at the Trinity site in New Mexico in 1945, created a thin layer of glass on the sand. But the area of glass in the Egyptian desert is vastly bigger.
Whatever happened in Egypt must have been much more powerful than an atomic bomb.