Gold fell $4.5 or 0.3% to $1,658.9 an ounce by 1107 GMT after rising to a session high of $1,658.0.
It has come off a 4-month low of $1,635.1 struck on December 20, but remains well below a record high of around $1,920 hit in September 2011.
For the year, gold is up around 6%, but well below a record of around $1,920 touched in September 2011, when a worsening debt crisis in Europe sparked a buying rush. US gold for February eased $4.00 an ounce to $1,659.7.
Gold is traditionally a safe-haven and inflation hedge that investors rush to in times of trouble, but it has lately behaved like any risk asset. The metal sometimes rises and falls with the stock market.
The euro fell to a session low against the dollar on Friday on year-end dollar buying from investors adjusting their portfolios and as traders took profit on the common currency's recent gains.
Global gold demand in 2013 should be led by further strength in Chinese demand and a recovery in India, helping the precious metal continue its bull run into its 13th year, the industry-backed World Gold Council has said.
Gold demand in India, the world's biggest buyer of the metal, was moderate on Friday as jewellers replenished inventory for festivals and the wedding season, but retail and investment demand remained sluggish.