The Hypatia stone, as it is known, is not only extraterrestrial in origin. It contains micro-mineral compounds not known to occur anywhere on Earth, not found in any other meteorites, and not known to occur anywhere in the Solar System. It's a discovery that raises some questions about the formation of the Solar System. Subsequent analysis revealed that the diamond-filled stone was not from any known comet or meteorite - its combined features were unique among known extraterrestrial materials. One hypothesis proposed that it might be a fragment of comet nucleus, shocked on impact, and another found that it was...