For example, cash is needed for exploring and further developing new diamond deposits.
The 1967 discovery of Orapa's diamond deposits aided this programme.
Contrary to its name, the area does not contain any diamond deposits.
But no one knows how rich a diamond deposit is under the field, which is the result of a volcano eruption 95 million years ago.
More precise figures, he said, depend on the shape of the diamond deposit.
The park, the only significant diamond deposit in North America, was opened by the state to private developers in 1989.
In the 1950s, diamond deposits were discovered in the area, about 700 km from its mouth.
There had been talk of potential diamond deposits in the Northern Territory.
There are diamond deposits in the basin of the Vishera River.
This turned out to be the world's largest known diamond deposit, larger than all the rest put together.