http://b4hntuy3fimfh2227vf4f74emnya7p35i5brtqujs6leqvtclfwvjbqd.onion/doc/physics/diamonds-crookes/The%20Project%20Gutenberg%20eBook%20of%20Diamonds,%20by%20William%20Crookes..html
The areas of the mines are: Kimberley 33 acres De Beers 22 acres Dutoitspan 45 acres Bultfontein 36 acres [15] In 1907 the total number of carats raised
from these mines was more than two
million and a half, the sales of which realised
£6,452,597. The most important mine outside the
Kimberley group is the new Premier Mine,
about 20 miles West-North-West of Pretoria,
where the famous Cullinan diamond
was found.