Gold prices are posting solid gains and are trading near their daily highs as midday approaches Tuesday. More bullish near-term technical postures for gold and silver prices are working to inspire chart-based buying interest in the precious metals markets. The recent slump in the U.S. dollar index is also working in favor of the precious metals bulls. The dollar index fell to a five-week low Tuesday. December Comex gold was last up $13.80 an ounce at $1,373.40.