Platinum futures plunged more than $19 an ounce, and gold was down about $5.
Prices of platinum futures are now poised to drop below $350 an ounce for the first time in more than five years.
Platinum futures fell the daily maximum allowed and other metals also dropped yesterday.
Platinum futures settled $6.10 to $6.40 higher, with October at $500.80 a troy ounce.
The prices of platinum futures rose substantially but gold and silver retreated.
Prices of platinum futures rose sharply yesterday on speculative buying.
As usual, the volatile platinum futures posted the largest declines.
Platinum futures prices moved sharply higher, with increased industrial demand cited for the gains.
Platinum futures plunged on reports the Japanese have developed an alternative auto pollution control device.
Platinum futures declined the $25 daily limit, undercut by the stronger dollar.
