Combined sulphur exists as sulphates, such as gypsum, epsom,baryte and sulphides such as galena, zinc blende, copper pyrites, etc.Traces of sulphur occur as hydrogen sulphide in volcanoes. Few organicmaterials like eggs, proteins, garlic, onion, mustard, hair and wool containsulphur. 0.03 – 0.1% sulphur is present in the earth’s crust.