Which of the following is not a naturally occurring iron ore?
The naturally occurring iron ores are compounds that contain iron combined with other elements such as oxygen, carbon, and sulfur. Out of the given options, FeCl2 is not a naturally occurring iron ore because it is a compound of iron and chlorine. Iron chloride is not found naturally in the earth's crust as an ore. Fe2O3, Fe2O3O3, FeCO3, and FeS2 are all naturally occurring iron ores. Fe2O3 is commonly known as hematite, Fe2O3O3 is not a known compound, FeCO3 is known as siderite, and FeS2 is known as pyrite or fool's gold.