The area has long been known for the rich sulfur mines there. Each day, workers gather sulfur from the crater floor and carry it nearly 2 miles to get paid.
Now think back to your days in chemistry class. What color flame does burning sulfur produce? That’s right, sulfur burns a brilliant blue.
Referred to as “the Blue Fire” by locals, flames at Ijen have long glowed blue, but the area wasn’t a tourist attraction until after National Geographic wrote about it in 2014.
Technically speaking, the lava itself is not blue, and some red/ orange flames can still be seen underneath the blue. In fact, it’s all the sulfur burning atop the lava that turns blue.
The color of the lava and molten materials found at volcanos can change color depending on the minerals present, but the Ijen volcano is one of the most vibrant, fantastic examples.
It’s a 2-hour nighttime hike to the top of the volcano to witness the phenomenon in person, which sounds like the trip of a lifetime to us. Just be ready for the smell!