You have probably heard about some of the volcanos in Indonesia. Here is one that is an active sulphur mine. At night the lava glows blue.
A couple of Frenchmen have made a doco but here is a link to some pics from another source.
http://sploid.gizmodo.com/spectacular-blue-lava-flows-at-this-indonesian-volcano-1498816568
A couple of Frenchmen have made a doco but here is a link to some pics from another source.
http://sploid.gizmodo.com/spectacular-blue-lava-flows-at-this-indonesian-volcano-1498816568