In India the diamonds are quarried from

Answer: (d) Panna

Panna is India’s diamond field.

The idea

Diamonds form deep within the Earth and can be brought upward by certain volcanic rocks. Weathering may later release them into river sediments. A trading or cutting centre can become famous for diamonds without being the deposit sought in a mining question.

Diamonds form at depth → Volcanic magma carries some upward → Diamond-bearing host rock reaches shallow levels → Weathering releases resistant crystals → Water can concentrate them in sediments

Why the others are wrong

(a) Golconda was a trading hub.

(b) Jaipur cuts gems.

The trap

Asked in 1987 and 1991.

Also know

Majhgawan anchors the Panna diamond area. Kimberlite and lamproite are primary host-rock terms; river-gravel deposits are secondary deposits. Hutti is a gold anchor and Koderma a mica anchor, useful contrasts within Indian mineral geography.