Britain's blue-chip index slid below the 6,000 mark this afternoon, the first time since August, as a rout in commodity prices weighed on miners.
The FTSE 100 closed down 2.8 per cent to 5,940.72, as copper prices which struck a two-week low and Credit Suisse downgraded the sector.
"Until China demand and emerging market currencies find a floor, it will remain challenging to put an absolute floor on commodity prices," a note from analysts at Credit Suisse said.
Glencore shares closed down 11.8 per cent, as rival Antofagasta slumped 6.7 per cent and Anglo American shed 6.4 per cent.
Read more: Glencore shares are tumbling
Oil prices also fell as much as 1.5 per cent, to $48.17 a barrel, amid uncertainty over whether global demand will be able to erode a huge surplus.
Insurer RSA managed to shrug off the gloom, closing up 0.9 per cent, despite rival Zurich pulling out of possible takeover talks yesterday.
The FTSE 100 hit a record high of 7,122.74 points in late April. Since then, it's lost ground, amid concerns over an economic slowdown in China, and the prospect of an interest rate rise in the United States.
China turmoil has hit commodities stocks because it's the world's largest consumer of raw materials. while an interest rate rise would increase the returns of other investments such as bonds and cash.