A perfect storm slammed gold and silver prices Friday. Selling from celebrity hedge fund managers, tighter U.S. sanctions in Turkey's gold-for-gas trade with Iran, liquidations ahead of the G-20 meeting in Moscow, and the Chinese Lunar New Year holiday and continued strength in the dollar were all blamed for the sharp nose-dive in precious metals. Spot gold prices tumbled 1.7% to $1,608 an ounce -- its lowest price since early August. In afternoon