Gold prices rose on Thursday in thin, yet supportive, year-end trading en route to a weekly gain, although an improved risk appetite capped bullion's rise.

Spot gold rose 0.4% to $1,809.70 per ounce by 1335 GMT, U.S. gold futures climbed 0.3% to $1,808.

Thin trading and Christmas buying are keeping gold above the $1,800 level, said Michael Langford, director at corporate advisory AirGuide. He added that the rise of risk-on investments ahead of Christmas, called a "Santa Claus rally", was creating a bit of a short-term positive for the metal.

Global shares, bond yields and riskier currencies all hit recent highs on Thursday as investor confidence grew on signs that the Omicron variant of COVID-19 might be less severe than feared, as well as robust U.S. economic data.

"The main driver for gold moving again above the $1,800/ounce mark are rising U.S. inflation expectations as gauged by the breakeven," said UBS analyst Giovanni Staunovo.

The dollar index, on course for a weekly dip, recovered slightly but stayed near a one-week low against riskier rivals, making gold less appealing for holders of non-U.S. currencies.

Gold climbs on weaker dollar, lingering Omicron worries

Helped by the subdued dollar, gold has so far added about 0.6% in a week truncated by the Christmas-eve market holiday on Friday, in what could be its second straight weekly gain.

"Gold faces technical resistance at $1,815 and $1,826, with geopolitical risks ahead potentially keeping gold supported, despite the tapering narrative," said Nicholas Frappell, a global general manager at ABC Bullion.

Spot silver gained 0.6% to $22.91 per ounce, and platinum edged up 0.1% to $965.28, rising 2.4% and 3.5% respectively so far this week, and on course for their best weekly showing in six.

Palladium added 0.3% to $1,886.95, and climbed about 6% for the week.