TIL Many bronze age peoples forgot what stone age tools were, and thought discovered ones as some kind of mystical talismans or signs from a thunder god

Also mistaken for fulgurite by the more naturalistically minded, apparently. Maybe most common in the Nordics, based on viking references?

Additional links:
https://www.nationalgeographic.com/science/article/100810-thor-thors-hammer-viking-graves-thunderstones-science
https://fi.wikipedia.org/wiki/Ukonvaaja [Finnish]