Platinum and palladium prices have climbed on the threat of further supply disruptions in South Africa after violence flared up this week at one of the country's mines.
Gold fell for a fourth session, hitting a six-month low.
Platinum futures for April delivery on Tuesday settled up 1.2 per cent at $US1,697.50 a troy ounce on the New York Mercantile Exchange. Palladium for March delivery rose 1.5 per cent to settle at $US764.15 a troy ounce.
Fighting between rival mine workers unions erupted on Monday at a South African mine owned by Anglo American Platinum Ltd, police said.
As hundreds of mine workers at a mine north of Johannesburg prepared to attack four members of the National Union of Mineworkers, security guards used rubber bullets to disperse the crowd.
At least 13 people were injured.
Clashes between NUM and members of newcomer the Association of Mineworkers and Construction Union led to months of violent strikes in South Africa's platinum mines beginning in August.
Workers at two Anglo platinum mines refused to work on Tuesday to protest against the shooting of colleagues by guards during the standoff.
This week's flare-up "served as a reminder that supply issues for platinum are not over yet," traders with TD Securities said in a note.
South Africa is the world's top platinum producer, and the No 2 producer of palladium. Mining companies there have been under pressure in recent years from rapidly rising costs that made some mines unprofitable. The threat of mine closures and related job losses have led to strikes and government mediation.
In January, Anglo American Platinum, the largest platinum mining company in the world and majority owned by Anglo American, said it would cut production in an effort to return to profitability.
Platinum and palladium both surged early this month to multi-month highs as traders bet that the company wouldn't be the last to cut production.
Gold fell on Tuesday, as investors remained cautious toward the metal after its lackluster recent performance.
The most actively traded gold contract, for April delivery, fell $US5.30, or 0.3 per cent, to settle at $US1,604.20 a troy ounce on the Comex division of the Nymex, the lowest ending price since August 2.
Gold has struggled in recent weeks, as signs of an improving global economy limited demand for the metal as a safe haven. Worries that the Federal Reserve would pull the plug on its easy-money policies this year have also hit sentiment.
"You're starting to see rotation out of the protectionary trade," said Zachary Oxman, a managing director with brokerage TrendMax. Some investors, he said, were moving "out of silver, gold, and back into stocks."
Accommodative monetary policy can draw investors to gold and other precious metals as they seek a hedge against the inflation that may result down the line.
Through Tuesday, benchmark gold futures were down 4.3 per cent this year.
"Investor confidence in gold is at rock bottom," VTB Capital analyst Andrey Kryuchenkov said in a note.
Nymex floor trading was closed on Monday for the US President's Day holiday.