In 1996 in the Egyptian Museum in Cairo, Italian mineralogist Vincenzo de Michele spotted an unusual yellow-green gem in the middle of one of Tutankhamun's necklaces.
The jewel was tested and found to be glass, but intriguingly it is older than the earliest Egyptian civilisation.
...An Austrian astrochemist Christian Koeberl had established that the glass had been formed at a temperature so hot that there could be only one known cause: a meteorite impacting with Earth. And yet there were no signs of an impact crater, even in satellite images.
http://news.bbc.co.uk/2/hi/science/nature/5196362.stm
