Forty-five countries engaged in the diamond trade finally signed a new scheme to stem the flow of "conflict" diamonds this week. The certification scheme, which will take effect on January 1, is the result of 30 months of negotiations. Alex Yearsley, a representative for Global Witness, which led the campaign against "conflict" diamonds, expressed reservations about the monitoring scheme. But overall, he said,"we are happy with the agreement. It is great that the governments signed up to it." He added: "Hopefully, it will stop a good 80-90% of conflict diamonds."