Is an iron ore homogeneous or heterogeneous?
It depends on the ore. An ore is typically composed of one or more ore minerals (the minerals that contain the elements you want to extract) but may contain gangue minerals as well (gangue minerals are not processed into a saleable product; common gangue minerals are quartz and calcite). Minerals that are processed for their iron content include hematite, magnetite, limonite (a mix of iron oxides and hydroxides such as goethite), and siderite. Many iron ores consist of relatively pure massive hematite, so these ores would be pretty homogeneous. Other ores may consist of the ore mineral(s) interspersed with other minerals or the host rock, which would be heterogeneous.