The eruption of the volcano Kawah Ijen in East Java, Indonesia.
Bright blue flame interested photographer Olivier Grunwald, who documented this natural phenomenon, publishing footage in National Geographic.
This unusual color of the flame caused by combustion of sulfur dioxide. The gases are pulled out from the cracks in the volcano at high pressure, where the flame temperature reaches 600 degrees Celsius (1112 degrees Fahrenheit).
Once they come into contact with air, the gas is ignited by throwing flames 5-meter height.
At night, the volcano becomes illuminated in electric blue light mountain mystical light begins to rise from the depths of the crater.