Very cool photos, nice to see rocks from a perspective I'd not seen before. I came across this recently - https://en.wikipedia.org/wiki/Thermoluminescence http

Very cool photos, nice to see rocks from a perspective I'd not seen before. I came across this recently - https://en.wikipedia.org/wiki/Thermoluminescence https://en.wikipedia.org/wiki/Thermoluminescence where it sounds like some rocks emit light upon heating.