kid, i like you already. sounds like a fucking awesome topic. i have a book called "blood diamonds" by greg campbell. its got loads of info on the diamond trade, you might want to have a search around for it. for a little contextual background to issues in africa, you might like "king leopold's ghost" by adam hoschild, and "european atrocity, african catastrophe" by martin ewans. the ewans book will be hard to find in a shop, look for it in a uni library, but i have seen many copies of the others in borders etc. i did both my year 11 investigation and my hex project on african themes, so its a passionate area for me.