Indonesian Kawah Ijen volcano spews blue molten sulphur lava Kawah Ijen volcano in East Java, Indonesia, produces molten suphur which leaks from its sides Miners funnel it in to a crater where they allow it to cool before breaking it off in order to sell The burning chemical appears red during the day but at night the blue flames become visible At first glance you might think the otherworldly light in these pictures comes from a nebula or another planet deep in outer space. In fact it is made by burning sulphur which pours from the side of the Kawah Ijen volcano on planet Earth, which is part of the Ijen volcano complex in East Java, Indonesia. Miners have run ceramic pipes from vents in the side of the mountain to collection points inside a large crater where the molten chemical is left to cool before being broken up and carried away. Out of this world: While these pictures may appear to be from another planet, they are in fact produced by burning sulphur here on Earth The molten chemical comes from the sides of the Kawah Ijen volcano in Indonesia and is directed through pipes by miners to collection points in a nearby crater While the sulhpur appears bright red during the day, at night it gives off an eerie blue light with flames that can reach up to five foot in height. The miners who rely on the sulphur for their livelihoods work in treacherous conditions at the bottom of the crater. They wear nothing other than t-shirts and trousers as they collect the yellow material, despite toxic fumes being given off and the fact that the molten sulphur is heated to more than 240F. They must also avoid the deadly turquoise-blue lake which takes up most of the crater floor, as it is made up of almost pure sulphuric acid, and would instantly kill anyone unlucky enough to fall in. Once the chemical element has cooled the miners break off blocks weighing up to 220lb and haul it away by hand in order for it to be sold The sulphur appears bright red during the day, but as the sun sets the blue flames - which can reach up to five foot in height - start to become visible They must also move solid blocks of sulphur weighing up to 220lb up a very steep slope in order to sell them, using nothing more than a basket and their bare hands. Photographer Olivier Grunewald, who captured some of these amazing shots, had to wear a gas mask during his expedition into the crater, and lost two lenses and a camera while trying to capture the mysterious pictures.