Mining stocks were performing well on Tuesday afternoon, tracking commodities prices higher on hopes that US leaders can work to avert the impending 'fiscal cliff'.A weaker dollar helped gold prices rise to around $1,700 an ounce earlier in the day after President Barack Obama last night presented an offer to raise taxes for those that earn over $400,000, a higher threshold than the $250,000 annual salary he had previously targeted, showing that he is willing to negotiate with House Speaker John Boehner.Also helping stocks was the International Energy Agency (IEA) which said that coal will come close to surpassing oil as the world's top energy source by 2017. According to the IEA's Medium-Term Coal Market Report, the world will burn around 1.2bn more tonnes of coal per year by 2017 compared to today, equivalent to the current coal consumption of Russia and the United States combined.Central Europe-focused hard coal and coke producer New World Resources surged this afternoon on the FTSE 250. FTSE 100 mining peers Vedanta, EVRAZ and Rio Tinto were also on the up.Precious metals group Polymetal rose after saying that it is to buy up the Svetlobor platinum exploration project in the Sverdlovsk region of Russia through two transactions. The company said that the acquisitions gives it meaningful exposure to platinum, "a precious metal with limited production outside South Africa and Zimbabwe, countries which face a material risk of significant supply disruptions" AIM-listed African Minerals said it is making significant progress on its projects including the expansion of its existing rail and port infrastructure in Pepel, Sierra Leone. In other news, tin consumption in China (the biggest user of tin) will rise by 4% to 152,000 metric tons in 2013, following a 5% slump this year, according to industry group ITRI.Top performing sectors so far todayIndustrial Metals & Mining 2,801.29 +2.16%Aerospace and Defence 3,960.91 +1.65%Technology Hardware & Equipment 917.74 +1.29%Automobiles & Parts 5,337.80 +1.20%Mining 19,742.31 +1.15%Bottom performing sectors so far todayMobile Telecommunications 3,660.94 -1.05%Insurance (non-life) 1,628.74 -0.72%Personal Goods 19,739.40 -0.50%Oil Equipment, Services & Distribution 23,771.40 -0.43%Pharmaceuticals & Biotechnology 9,518.23 -0.14%BC