Green Gold? Wal-Mart and Tiffany are trying to clean up the gold-mining industry. Not everyone i

It's the gold that Pam Mortensen has come here to see. Mortensen, 52, is in charge of buying fine jewelry for Wal-Mart. And recently she has moved the world's largest retailer to the forefront of a loose alliance of businesses and environmental groups that have set out to clean up gold mining, one of the world's dirtiest industries.