iron ore

This term refers specifically to the raw mineral state of iron before it is processed. It is distinct from iron as a pure metal; iron ore is the geological source material that must undergo smelting in a blast furnace to remove impurities and oxygen.

As a mass noun, it describes the substance in general. While one might refer to different types of ores (such as hematite or magnetite), the term "iron ore" itself is typically treated as uncountable in industrial and geological contexts, referring to the bulk material being mined or transported.