(Adds that Cliffs Natural Resources plans to spend $1 billion in capital expenditures this year.)BOSTON ( TheStreet) -- The materials sector is leading the league in terms of returns this year, with a 10.8% gain, almost equal to its loss of 11.6% last year when it was one of the worst performers. The next-best performer, financials, has risen 8.2% this year, while the broader S&P 500 Index has climbed 4.7%. Materials companies have mundane product offerings, such as fertilizer, beverage cans and paper products, but this is the stuff that makes the world grow. And the gains of stocks in this sector can't be ignored as many are well up into double-digits, and one has soared 45% this year. Always highly cyclical, the materials sector may well continue its strength into the year, according to analysts. Morningstar says that "despite global economic weakness, we expect demand for commodities in the medium term to be driven by ongoing demand from emerging markets and an eventual cyclical upturn in developed markets." This sector got hurt in 2011 as economic weakness and uncertainty took their toll. The hamstrung U.S. economy and the sovereign debt crisis in Europe hurt demand from many of the big materials consumers, especially the construction industry. But slow signs of recovery in North America and the seemingly insatiable appetite of emerging markets for materials used in infrastructure construction, farming and chemicals for consumer goods, are providing support for a rally. Here are 10 materials-sector stocks that have "buy" or "strong buy" recommendations and either a four- or five-star rating from Standard & Poor's Stock Reports: 1. Alcoa ( AA) Company profile: Alcoa is one of the world's largest producers of aluminum and the only top-rated stock in the aluminum materials sub-sector, which is up 20% this year. Investor takeaway: S&P gives it a "buy" rating with four stars out of a possible five. For fiscal 2012, analysts estimate that Alcoa will earn 61 cents per share and that will grow 59% in 2013. Its shares have a 1.15% dividend yield. Analysts give it five "buys," five "buy/holds," eight "holds," one "weak/hold," and two "sells," said S&P. 2. Rio Tinto ( RIO) Company profile: Rio Tinto, based in London, is one of the world's largest mining companies with a market value of $115 billion. It is the leader in the diversified metals and mining sub-sector, which is up 23% this year. Investor takeaway: Its shares are up 24% this year. Over the past three years, its shares have an average annual return of 46%. This company has hard-to-replicate mineral reserves and low-cost operations, due to its massive scale. S&P has it rated "strong buy" with five stars, its highest. Analysts give it four "buy" ratings and one "buy/hold," according to an S&P survey. For fiscal 2012, analysts estimate the company will earn $8.26 per share. Its shares have a 1.95% dividend yield. 3. Cliffs Natural Resources ( CLF) Company profile: Cliffs is the largest supplier of iron ore pellets to the steel industry as it operates nearly half of the total iron ore mine capacity in North America. It is a leader in the steel sub-sector, which is up 12% this year. Cliffs said it expects to spend $1 billion on capital investments this year, including $700 million on growth and productivity improvements and $300 million on sustaining capital. That's up from the $880 million the company spent in 2011. Investor takeaway: Cliffs Natural Resources shares are up 16% this year. S&P gives it a "strong buy" rating with five stars, its highest ranking. Analysts polled by S&P give it nine "buy" ratings, eight "buy/holds," and four "holds."