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Global mining giant Rio Tinto (NYSE: RIO) released interim figures on Thursday, and they were described by chairman Jan du Plessis as "another set of record-breaking results."

Earnings and cash flow both reached new highs for the company, with net earnings up 30% from last year, reaching $7.6 billion from the $5.8 billion reported in the first half last year. Cash flow was up 31%, to $12.9 billion.

An interim dividend of $0.54 per share was announced, which is 20% up on last year's first-half figure of $0.45.

But we all know how fickle the investment world can be -- the share price is down more than 3% at the time of writing. Why? Well, despite the glowing headline figures, analysts had been expecting even more. And fears of rising costs and general economic weaknesses led to further jitters amongst shareholders.

Economic fears
The company, which is the world's second-largest producer of iron ore, tempered its positive outlook with some clear risks, with chief executive Tom Albanese saying: "However, there are important risks to this outlook related to the pace of credit tightening in developing countries and the threat of financial crises arising from sovereign debt problems in Europe and the United States which could destabilize commodity markets."

After the U.S. only just managed an eleventh-hour deal to lift its borrowing limits and avoid running out of cash, and the Centre for Economics and Business Research raised fears that Italy is likely to default on its debts, those risks are clearly not to be dismissed lightly.

But looking on the bright side, the demand from China seems insatiable, with imports of coal increasing nicely. And steel demand in China -- Rio Tinto's iron-ore production is the biggest contributor to the company's profits -- is still rising too, in line with the country's general economic growth, which is expected to come in at 9.5% this year.

Out of favor
Overall, the commodities and minerals markets seem to be fast falling out of favor with investors, and Rio Tinto's share price has fallen by nearly a fifth in the past month -- with the past week's chart tracing the famous "Beachy Head" formation.

On a forward P/E of under 8, with net debt having been slashed by the past few years of top profits (though admittedly paying only a modest dividend of less than 2%), are Rio Tinto's shares, along with much of the sector, oversold now?

They just might be.

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