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]
Kurzgesagt did this video where they crammed all of Earth’s history in an hour. Basically you look at a barren wasteland for most of the time until life finally goes macroscopic and then all of humanity happens in less than a second
I sat through the whole thing and it’s still incomprehensible