Where were Indian diamonds historically mined?

• A. Rivers and valleys of southern India
• B. Kimberlite pipes in central India
• C. Coastal beaches
• D. Mountain caves

Answer: (A)

Diamonds in India were historically obtained from alluvial placer deposits in river sediments. Over time, diamonds eroded from their primary source rocks in the Deccan region were transported by rivers and settled in the gravels of riverbeds and valleys in southern India. These river gravels could be mined relatively easily, which is why southern India’s rivers and valleys became the classic historical source of Indian diamonds, notably around the Golconda/Kollur area. The idea to remember is that, while diamonds form deep underground in kimberlite-like rocks, the stones reached the surface and accumulated in river gravels that people could mine, making river valleys in southern India the traditional source. Coastlines and mountain caves aren’t the typical historical sources for Indian diamonds, and primary kimberlite pipes, though real sources, were not the primary method for historical mining in the region.