Mining stocks were the biggest risers on Thursday as the price of precious metals jumped.Randgold Resources, Fresnillio, Anglo American and Antofagasta were among the miners who gained on an increase in commodity values. COMEX Gold was up 4.55% to $1,367.10 per ounce at 13:45 while silver and copper rose 7.31% to $23.14 per ounce and 2.07% to $334.65 per pound respectively. On the downside, telecommunication stocks slumped, most notably Vodafone, which has been coming down from the biggest high since 2001 on Monday.Supermarket chain Tesco was down after Nomura cut its rating from 'buy' to 'neutral' and reduced its target price to 400p from 430p.Top performing sectors so far todayMining 17,450.24 +3.52%Industrial Metals & Mining 1,642.04 +3.46%Beverages 15,316.35 +3.44%Food Producers & Processors 7,067.36 +2.79%Construction & Materials 4,225.35 +2.34%Bottom performing sectors so far todayIndustrial Transportation 3,172.38 -0.86%Mobile Telecommunications 4,883.87 -0.86%General Industrials 4,184.42 -0.21%Fixed Line Telecommunications 3,918.99 -0.05%Aeronautics and Defence NULL 0.00%RD