1. Iron Ore (Backbone of Modern Industry):
India possesses rich deposits of high-grade hematite and magnetite:
- Varieties: (i) Magnetite ($\text{Fe}_3\text{O}_4$): Black ore, magnetic, highest iron content ($> 70\%$); (ii) Haematite ($\text{Fe}_2\text{O}_3$): Reddish-brown ore, $60-70\%$ iron (most common industrial ore in India); (iii) Limonite and Siderite (inferior quality).
- Leading Producer States & Mining Belts:
• Odisha (Leading Producer): Mayurbhanj (Gurumahisani, Badampahar) and Kendujhar (Kiriburu).
• Jharkhand: Singhbhum (Noamundi, Gua).
• Chhattisgarh: Durg (Dalli-Rajhara) and Bastar (Bailadila mines, exporting high-grade lump ore to Japan via Visakhapatnam port!).
• Karnataka: Bellary, Kudremukh (slurry pipeline to Mangaluru port), and Bababudan hills.
2. Bauxite (Ore of Aluminium):
Hydrated aluminium oxide ($\text{Al}_2\text{O}_3\cdot 2\text{H}_2\text{O}$). Used in aircraft fuselages, electrical cables, automobile components. Leading state: Odisha (Kalahandi, Koraput, Panchpatmali), Jharkhand (Palaum, Lohardaga), and Gujarat.
3. Manganese Ore:
Essential ferro-alloy used in steel manufacturing (nearly $10\text{ kg of manganese}$ is required to manufacture $1\text{ tonne of steel}$ to increase tensile strength and remove oxygen/sulfur). Also used in bleaching powder, dry batteries, and paints. Leading states: Madhya Pradesh (Balaghat), Maharashtra (Nagpur, Bhandara), and Odisha (Sundargarh).