Randgold Resources jumped after Numis upgraded the miner to 'buy' from 'add', while the same broker also gave sector peer Antofagasta a boost after upgrading it from 'reduce' to 'hold'.Fresnillo and Polymetal also gained as a weaker dollar prompted a jump in gold and silver prices.Rolls-Royce was in demand after the power systems firm announced an order for its Trent 1000 engines from Nordic airline Norwegian, while postal operator Royal Mail also rose after saying it has done a deal to end a competition probe in France.Supermarket group Sainsbury also came off recent declines with a gain of more than 2%.Vodafone was among the worst performers after a downgrade from Nomura. The broker cut its rating for the telecom from 'neutral' to 'reduce', saying that "competition [is] set to increase, not decrease", despite the stock being price for "market repair".Aviva and Kingfisher were trading lower after going ex-dividend. Travis Perkins, Weir Group and WPP also went ex-dividend.FTSE 100 - RisersRandgold Resources Ltd. (RRS) 4,317.00p +6.59%Fresnillo (FRES) 763.50p +5.53%Severn Trent (SVT) 1,908.00p +3.14%Petrofac Ltd. (PFC) 1,004.00p +2.97%Rio Tinto (RIO) 3,068.00p +2.64%Sainsbury (J) (SBRY) 231.70p +2.21%Antofagasta (ANTO) 689.50p +2.15%ARM Holdings (ARM) 873.50p +2.10%Anglo American (AAL) 1,366.00p +2.09%Burberry Group (BRBY) 1,495.00p +1.98%FTSE 100 - FallersKingfisher (KGF) 303.40p -2.97%Vodafone Group (VOD) 199.65p -2.28%Royal Dutch Shell 'B' (RDSB) 2,326.00p -1.82%Aviva (AV.) 504.00p -1.75%Persimmon (PSN) 1,300.00p -1.66%International Consolidated Airlines Group SA Royal Dutch Shell 'A' (RDSA) 2,246.50p -1.51%Tullow Oil (TLW) 567.50p -1.48%TUI Travel (TT.) 361.60p -1.47%Marks & Spencer Group (MKS) 397.20p -1.34%