King Tut's Necklace Gem Is Actually Natural Glass From Meteorite Impact

The BBC has an article on how a gem in one of King Tut's necklaces is actually made of natural glass that formed from a meteorite that exploded over the Western Desert.Here is an article on on the crater, called El Kebira ( الكبيرة "The Big" in Arabic), and here is a satellite photo.I was able to locate the crater on Google, marked on Wikimapia. This straddles the border of Egypt and Libya.And here is a Slashdot discussion on this crater, meteorite and glass.