Here's a pretty complete run-down by my gemologist friend Elise Skalwold, who has deep Norwegian roots: VIKING SUNSTONE
Ancient people had trial and error on their side—and lots of Time. Writing helped a great deal and organization—thats why Egypt advanced—necause the Egyptians were in a place where all the germs of Africa came down the Nile—they became the best doctors in the Ancient World—and developed cures and drugs that could rival a 19th Century Western Sawbones. They did this because they had to. same with the Vikings (Norse) They were a sea faring people and needed to develope fine ships and ways to navagate—They had writing too—the Runes.
Thanks!