Mining stocks were making gains on Tuesday with blue-chip players Polymetal, BHP Billiton and Rio Tinto providing a lift to the sector.Precious metals producer Polymetal rose after entering into a definitive agreement with AIM-listed Ovoca Gold to acquire the Russian legal entity Olymp, which holds the mining and exploration license for the Olcha gold-silver deposit.Vitaly Nesis, Chief Executive Officer of Polymetal, said: "Olcha represents a good opportunity to add another high-grade source of feed for the Lunnoye plant. In addition, Olcha is a natural extension of our portfolio of advanced exploration properties in the Magadan Region". BHP was on the up after Nomura named it as its preferred stock in the global metals and mining industry, reiterating its 'buy' recommendation and 2,350p target price for the shares.Rio Tinto said that it has agreed to sell its 57.7% stake in Palabora Mining Company for $373m.FTSE 250 coal miner Bumi was also in demand on speculation that its Chief Executive Nalin Rathod could resign from the board tomorrow amidst an investigation into "potential financial irregularities" at its division, Bumi Resources, in Indonesia. In small cap news, AIM-listed zinc and lead processing firm Berkeley Mineral Resources jumped after saying that its stockpiles at the Kabwe mine, Zambia, can achieve suitable recovery rates to produce concentrates of more than 40%, and up to 48%, which will then be processable into saleable metal.Top performing sectors so far todayIndustrial Metals & Mining 2,622.37 +2.60%Construction & Materials 3,288.14 +1.26%Mining 19,050.77 +1.10%Food & Drug Retailers 4,180.74 +0.93%Electricity 9,062.54 +0.92%Bottom performing sectors so far todayBeverages 13,297.90 -1.10%Aerospace and Defence 3,928.25 -0.97%Personal Goods 20,375.85 -0.94%Chemicals 9,034.23 -0.79%Industrial Transportation 2,418.59 -0.76%BC