Explanation:

A large group of diamond deposits extends North-East on a branch of the Vindhya Range for 150 miles (240 km) or so, and is known as the Panna group.They do not cover an area of more than 20 acres (81,000 m2). Great pits, 25 feet (7.6 m) in diameter and, perhaps, 30 feet (9.1 m) in depth, are dug for the sake of reaching the diamond conglomerate, which, in many cases, was only a very thin layer. No really large diamonds have come from this area. The most productive mines were in the 1860s and were found in Sakaria, around 20 miles (32 km) from Panna.