Hochschild shares fell on news of a proposed mining levy in Mexico, where a number of the company's operations are located. The news also hit African Barrick Gold, which was already under pressure after its Chief Operating Officer last week quit. Shares in Petra Diamonds were lower - despite a strong set of annual results - after the firm warned that certain South African mines were affected by industrial action on August 29th. The industrial action has ended and normal operations are expected to be up and running from Monday, it said. Looking ahead at the market conditions, the rough diamond industry is anticipated to remain steady in the fiscal year 2014, due to constrained supply and a firmer US sector and continued growth in China. Petra swung to an annual profit driven by a rise in revenue and production along with tight cost control and operational expansion. Bumi shares were on the rise after it, Bumi plc, said its separation from the Bakrie Group and PT Bumi Resources will be completed by November 2013. In July the Indonesian thermal coal producer announced that it had agreed to sell its 29.2% interest in Bumi Resources to the Bakrie Group for $501m in cash.FTSE 250 - RisersDunelm Group (DNLM) 997.50p +6.12%Xaar (XAR) 800.00p +4.03%Elementis (ELM) 265.30p +3.75%PayPoint (PAY) 1,128.00p +3.49%NMC Health (NMC) 324.90p +3.37%Genus (GNS) 1,367.00p +3.25%Beazley (BEZ) 216.70p +3.04%Salamander Energy (SMDR) 125.70p +3.03%Bumi (BUMI) 210.30p +2.79%Ashmore Group (ASHM) 390.30p +2.74%FTSE 250 - FallersHochschild Mining (HOC) 236.10p -14.46%African Barrick Gold (ABG) 147.80p -9.99%Polymetal International (POLY) 663.00p -6.55%888 Holdings (888) 159.30p -3.45%TalkTalk Telecom Group (TALK) 252.00p -2.14%Cobham (COB) 295.50p -1.93%Kazakhmys (KAZ) 295.40p -1.89%Atkins (WS) (ATK) 1,219.00p -1.61%Perform Group (PER) 556.00p -1.59%Petra Diamonds Ltd.(DI) (PDL) 119.00p -1.49%NR