document: The leading index closed down 69.63 points at 6231.89.
  Miners more than doubled earlier losses to leave Antofagasta down more than 6%. Others, including Anglo American and BHP Billiton were down 4%.
  HOusebuilders all but wiped out their earlier falls. Taylor Wimpey ended flat and Berkeley Group ended less than 1% down after a report from chartered surveyors forecasted a short-term drop in UK house prices over the next three months.
  Rolls-Royce was also a loser, with a 2% fall.
  The chief executive of Rolls-Royce has warned staff that the engineering firm is behind with deliveries to customers, according to the Financial Times.
  Vodafone fell about 5% after it agreed a deal to merge its New Zealand operations with Sky Network Television.
  On the FTSE 250 builder Bellway was also caught in the general decline of construction shares, with a 1% fall.
  That was despite an upbeat trading statement.
  "That survey from RICS [Royal Institution of Chartered Surveyors] about a first possible drop in house prices since 2012, is clearly spooking people," said Russ Mould, investment director at AJ Bell.
  "It is tax-related and maybe a little bit Brexit related, but some will be wondering whether there are more fundamental factors slowing us down, as prices are just at such high levels."
  Flybe shares ended 5.5% lower, despite returning to profit.
  On the currency markets, the pound was down 0.3% against the dollar at $1.4466 but rose 0.3% against the euro to â‚¬1.277.
summary: (Close): A fall in mining shares hit the main indexes in London, with the FTSE 100 closing down more than 1%.