But, advocacy groups said in a statement, without "regular, independent monitoring of all national diamond control systems, the overall process remains open to abuse."

Criticism on Porter's national diamond model resolves around a number of assumptions that underlie it.

A Canadian National diamond crossing allows 'foreign' trains to Vancouver waterfront.

Michael Porter's National Diamond framework resulted from a study of patterns of comparative advantage among industrialized nations.

Endiama E.P. (Empresa Nacional de Diamantes E.P.) is the national diamond company of Angola and it is the exclusive concessionary of mining rights in the domain of diamonds.