And there of course is a scientific explanation for this:

Tall, mountainous stratovolcanoes like Mount Fuji remain silent for many hundreds of years before unleashing their cataclysmic fury on the world. Volcanoes on Io, one of Jupiter’s innermost moons, produce spectacular eruption columnsthat reach heights of 500 kilometers (310 miles) that are literally out of this world.  In any case, the lava produced tends to be an orangey-red color. Incredibly, a volcanic complex in Indonesia that goes by the name of Kawah Ijen bucks this trend: When it erupts, its lava burns an iridescent blue.

This is amazing and we hope you get a chance to check one of these things out.

(but only with a professional tour guide 😉