Iron is an essential element for the production of red blood cells and overall health of the body. Ferrous Sulphate is an iron supplement that is used to treat or prevent iron deficiency in the blood. Iron sulphate, green vitriol, and iron vitriol are all names for ferrous sulphate. The solid material resembles tiny crystals in its natural condition. Because the crystals are generally yellow, brown, or bluish-green, ferrous sulphate is also known as green vitriol.