Bailadila mines are known for

Concept: India's mineral geography groups major deposits into distinct belts, each linked to a specific mineral. Bailadila, in the Bastar region of Chhattisgarh, forms part of India's largest iron-ore belt and is operated by the state-run miner NMDC.

Application: The Bailadila hill ranges hold some of the world's finest hematite iron-ore deposits, spread across more than a dozen numbered deposits with reserves running into several hundred million tonnes. Ore mined here moves by the Kirandul-Kottavalasa railway line to Vishakhapatnam port for domestic steel plants and for export. This iron-ore identity is exactly why Bailadila is correctly matched with Iron-ore.

Cross-check: none of the other minerals fits Bailadila:

• Gold is mined at Kolar Gold Fields and Hutti, both in Karnataka — a different state and a different resource belt.

• Mica is concentrated in the Koderma-Giridih belt of Jharkhand, far from Chhattisgarh's Bastar hills.

• Diamond mining in India is centred on the Panna belt of Madhya Pradesh, a mineral region distinct from Bailadila's own hill ranges.