Stock image. Precious metals and copper prices plunged on Friday as investors took the nomination of a new Fed chair as an excuse to book profits on the metals which have rallied to record highs this week.Gold futures dropped as low as $4,700 an ounce before recovering some of those losses in afternoon trade only to succumb again to some late selling. Gold for delivery in April, the most active contract, closed at$4,745 an ounce down 11.4% or $600 an ounce on the day. It was the biggest intra-day decline s ...