The Argyle mine in Western Australia is one of the world’s largest diamond producers by volume, producing more than 750 million carats of rough diamonds since operations began in the 1980s. Most of the diamonds mined there are of relatively low quality. However, it is the primary source of the rare and valuable pink diamond, producing more than 90% of the world’s supply, and is also a major source of champagne, cognac, and blue diamonds. What percentage of Argyle’s diamonds are gem quality? Discuss