UK shares ended almost 18 down at 6,375 as traders went shopping it seemed on "Black Friday) and miners weighed heavily.
US markets were only open for a half day after Thanksgiving yesterday, so no real cues from that side of the pond.
"Gains are proving hard to sustain as the week comes to an end, and with US markets on a half day and important events looming, most investors are struggling to find a rationale to keep buying into equities," said Chris Beauchamp, at spreadbetter IG.
"Two days of gains, helped along by thin volumes, have given way to modest losses."
The big loser again was Anglo American (LON:AAL) shedding over 8% as it reported the closure of its Drayton coal mine in Australia next year .
Fellow major silver miner Fresnillo (LON:FRES) dropped 4.54% to 715p, while Randgold Resources (LON:RRS) dropped 4.29% to 3,997p.
In the small cap world, shale gas specialist IGas (LON:IGAS) surged over 13% as the UK government seems poised to overrule Lancashire council and allow fracking.
Other notable gainers were Golden Saint Resources (LON:GSR) the diamond and gold firm, focused on Sierra Leone, which added 7.69% to 0.035p.
This week the firm said it had brought in£170,000 via a share placing, it revealed, as it gave an operational update and reported on board changes. The net proceeds will be used for general working capital, the mining group said.
The firm issued 680 million new shares at 0.025 pence each - around a 33% discount to yesterday's closing price of 0.0375p. Also today, Tech and video group Forbidden Technologies (LON:FBT) added almost 12% to 7.12p.