### Kawah Ijen
Indonesia — Super-heated sulfur gases escape this volcano and ignite in the air, creating spectacular, leaping electric-blue flames.
The internet is full of rumors about a magical volcano in Indonesia that erupts "blue lava." Let's bust that myth right now: naturally occurring blue lava doesn't exist on Earth. Lava is molten rock, and it always glows red or orange. But Kawah Ijen does have glowing blue rivers spilling down its rocky walls—they just aren't made of rock. They are massive chemical fires.
Deep inside the volcano, immense amounts of highly pressurized sulfur gas are heated to a blistering 600°C (1,112°F). When this super-heated gas escapes through cracks in the rock (called fumaroles) and hits oxygen-rich air at the surface, it spontaneously ignites. The intense heat causes "electronic excitation." The sulfur's electrons get energized, and when they return to a stable state, they release their excess energy as a brilliant blue-violet light.
Sometimes, this burning sulfur gas condenses into a liquid. It continues to burn blue as it flows down the crater walls toward the world's deepest, highly acidic turquoise crater lake. It looks exactly like neon lava, proving that real chemistry is way cooler than fake internet photos.