In addition, investors were worried about the prospect of a contested US election, Reuters reported.
The market also awaits news from China's plenum - which will set the country's next five-year plan - which ends today, Marex Spectron's Alastair Munro noted.
Gold has dropped US$30 an ounce over the past 24 hours to $1,878 an ounce on the spot market.
Base metals except lead closed lower on the London Metal Exchange.
Mining majors sank in London, where Fresnillo finished 6.1% lower and Anglo American fell 5.07%.
Most gold equities closed lower in Toronto.
Eldorado Gold (TSX: ELD) lost 8.65% and Barrick Gold was down 3.37%.
On the TSX Venture Exchange, GGX Gold offered a contrast, closing up 31% to C19c as it reported high-grade assays from sampling at its Gold Drop property in British Columbia.
One of the surface rock chip grab samples returned 23.5g/t gold, 437g/t silver, 198g/t tellurium and 0.7% lead.
US futures were up but elsewhere, futures were pointing to a downbeat day.