Sulphur deposits in the Krafla lava field, Iceland.

The Krafla eruption 1975 began near Mývatn and Namafjall. This place is a well known as part of the active volcanic zone of Iceland. Sulphur is a chemical element ( symbol S ) which occurs in two forms but in Iceland, only elemental sulphur is found. Solfatares, openings in the earth crust that emit hydrogen sulphide ( and other gasses) which, in contact with oxygen, turns into elemental sulphur and sulphur dioxide. It has been mined in parts of Iceland since the middle ages and only ceased production in the 19th century.