New York - The Rapaport Group of diamond traders on Thursday said it would boycott diamonds from Zimbabwe's Marange field, which has been widely associated with human rights abuses.The boycott call from the group's chairman, Martin Rapaport, underlined controversy over the human rights situation in the Marange field and the wider role of so-called blood diamonds in fueling war and rights abuses.Rapaport said companies continuing to trade in diamonds from the Marange field would be expelled from the trade group.Such trades are already illegal in the United States, which has imposed sanctions on the Marange mines, but Rapaport said trade in such diamonds also harms the industry's reputation."You can ruin your reputation very easily by finding yourself on the wrong side of the human rights issue in a world where consumers are becoming more sensitized to it," he said in a conference call with Rapaport members."We at RapNet are going to make extreme efforts to ensure that, to the best of our ability, the diamonds we offer are non-Marange."He urged Rapaport's 6,750 trading members in 78 countries to be on the lookout for the characteristic green tinge of Marange diamonds."We want members to honestly, responsibly and reasonably investigate where the diamonds are coming from," he said. "Explain to your suppliers: look this is an important issue for us for legal reasons, for moral reasons."The Marange field has been at the center of years-long controversy over alleged abuses by President Robert Mugabe's army, and the Kimberley Process, an international blood diamond watchdog, has suspended exports from there.However, this year the Kimberley Process allowed two companies to start exporting from Marange, a decision supported by China and India but opposed by Western nations, rights groups and the industry.Zimbabwe is said to have stockpiled gems now estimated to be worth up to $5.0bn.