Gold slumped as expectation for QE3 in the US faded. In Fed's Beige Book, the bank stated that US economy continued to expand gradually in the last two months due to improving real estate market and strong retail sales.
Silver slid on increased risk-aversion among market participants ahead of Ben Bernanke's speech at Jackson Hole Symposium due on Friday.
Platinum was slightly lower on progress in talks between South African government, labour unions and platinum producers regarding recent strike at Lonmin's mine.
Palladium was the top-loser after North American Palladium reported that it is likely to reach an agreement with its workers at Thunder Bay mine.