Another great example of "structural" blue that can be created artificially by heating steel: https://www.youtube.com/watch?v=NhjiIPohUyw https://www.youtube.c

Another great example of "structural" blue that can be created artificially by heating steel: https://www.youtube.com/watch?v=NhjiIPohUyw https://www.youtube.com/watch?v=NhjiIPohUyw