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]
Someone pointed a temperature gun (for Covid testing) at me and for a brief moment, I forgot what they were.
When they’re uncovered 100 years from now, they’ll think we shot lasers at each other.
Don’t we though?