diamond news, page-1798

http://www.gia.edu/gems-gemology/WN13-advances-diamond-geology-shirey

"For economic geologists, the most important point is the striking correspondence between the oldest Archean portion of a craton and diamond occurrences, especially those hosted in kimberlite, the main carrier and hence “ore” of gem-quality diamond. This relationship, first formalized by Clifford (1966) and known as Clifford’s Rule, implies that the diamondiferous kimberlites erupted through the oldest Archean portions of the cratons, whereas non-diamondiferous kimberlites erupted through younger rocks. This relationship is nowhere more evident than the Kaapvaal craton, where all of the diamondiferous kimberlites are “on-craton” and all of the “off-craton” kimberlites are diamond-free. We will examine the geologic explanation for this below."

Our Botswana concession is located on the Limpopo belt, as is the Orapa Mine.

Our Lulo Concession is located on the Kasai craton, as is the Catoca mine.

Both the Limpopo belt and Kasai craton belong to the oldest cratons, i.e. the Archaean craton/belt.

Bingo!