Bauxite is the ore of:

Bauxite is the principal ore of aluminium. It is a hydrated oxide of aluminium, mainly gibbsite, boehmite and diaspore, with iron oxide and silica as impurities. Alumina is extracted from it by the Bayer process, which dissolves the alumina in caustic soda and leaves behind red mud. The metal is then obtained by the Hall-Héroult process, which electrolyses molten alumina dissolved in cryolite.

Why the others are wrong:

• Iron: the ores are haematite, magnetite, limonite and siderite.
• Copper: the ores are chalcopyrite, malachite and bornite, with chalcopyrite the main commercial source.
• Gold: it occurs mostly native or as tellurides and is recovered by cyanidation, not from any bauxite-type ore.

Core concept: ore identification is a static fact, but it links to the Mains mineral resources and industry sections, especially India's aluminium base. India is among the top bauxite producers, with Odisha leading in output, followed by Gujarat, Jharkhand and Chhattisgarh. Check current production figures before quoting them, as they change every year.

Trap: candidates sometimes confuse bauxite with laterite or red mud, or pick iron because bauxite-bearing rocks are iron-rich. Ores are named for the metal they yield, so bauxite gives aluminium.