One-time NBA star Dikembe Mutombo has made a worldwide name for himself sponsoring humanitarian projects and noble causes in his native Africa, so it was only natural that two State Department officials would meet with him in November 2010 as part of his effort to bring more attention to the bloody trade in conflict minerals that has bedeviled his homeland, the Democratic Republic of Congo. Less than two weeks later, according to a U.N. report, Mutombo was in New York on a more personal cause — trying to interest a Houston oil executive in a $10 million deal to buy 1,045 pounds of gold from the mines of eastern Congo, the heart of the conflict mineral trade.