Fe may combine with oxygen and hydroxyl ions to form which mineral?

The combination of iron (Fe) with oxygen and hydroxyl ions results in the formation of goethite. Goethite is a common secondary mineral and an important iron ore, often found in soils and other weathered environments. It has the chemical formula FeO(OH), indicating that it consists of iron bound to hydroxide and oxide components.

In contrast, hematite primarily consists of iron oxide (Fe2O3) and does not contain hydroxyl ions. Albite is a plagioclase feldspar mineral, composed of sodium and aluminum silicates, and has no direct relation to iron, oxygen, or hydroxyl ions. Kaolinite is a clay mineral made up of aluminum silicate and does not involve iron in its structure. Thus, the unique bond of iron with both oxygen and hydroxyl ions leads to the formation of goethite, making it the correct answer to the question.