Gold futures settled lower Tuesday for a fourth straight session, with the precious metal falling to the lowest value in about three weeks, breaching the psychologically significant value at $1,800 again. December gold shed $22.50, or 1.2%, to settle at $1,783.80 an ounce, marking the lowest finish for a most-active contract since Nov. 3, FactSet data show. The four-day slide also matched the longest string of declines for the contract for the precious metal since the period ended April 30.