Philosopher's Stone
Written by
William Messner-Loebs (writer), Adam Kubert (artist)
Released 11/1986
Published in Comico's Jonny Quest #6: Jonny Quest and Jade brought back an object from the previous adventure which is defying Dr. Quest's abilities to analyze it. It is super dense and may date from a very long lost civilization called Mu. There are others who will do anything to get hold of it.