Spot gold fell to $423.20/423.90 per troy ounce by 1600 GMT from $425.50/426.20 late in New York on Tuesday. Silver was down at $7.18/7.21 from $7.32/7.35.
The euro had earlier hit session lows after news of a blast in the province of Bushehr where Iran has a nuclear power plant.
Most of the gains disappeared after Iranian state television quoted a senior government figure as saying no signs of any explosion had been found.
"I guess as long as we don't receive confirmation that the blast really was really an attack, this is rather a non-event," one dealer said of the Iran report.
Greenspan was delivering testimony before the Senate Banking Committee. He will make the second part of this twice-yearly testimony on Thursday.
Analysts were still maintaining a bullish picture for gold, despite the possibility of short-term losses.
"Greenspan's comments are only modestly dollar-positive, he's speaking again tomorrow so its hard to believe we will see another major move in the euro and gold before then," Barclays Capital analyst Kamal Naqvi said.
For silver, Standard Bank said in a daily report that the market faced an extended period of consolidation between $7.00 and $7.35 after aggressive selling in Asian trade overnight.
Platinum edged up to $854.00/858.00 from $850.00/854.00 late in New York on Tuesday.
The market was steadying from Tuesday's sharp drop compounded by a report forecasting a platinum market surplus from refiner Johnson Matthey.
Palladium dipped to $180.00/184.00 from $180.00/184.00.