There's an oh-so-interesting rumor afoot: Could it be that the Chinese, who not long ago partnered with Alcoa (NYSE: AA) to acquire a stake in London-based mining giant Rio Tinto (NYSE: RTP), could be about to tie into an even bigger piece of more gigantic mining and metals behemoth BHP Billiton (NYSE: BHP)?

While the report has since been denied by a Chinese official, that at least was the conjecture on Tuesday. Last quarter, Aluminum Corp. of China (NYSE: ACH) and Pittsburgh-based Alcoa combined to acquire a stake in Rio Tinto. Specifically, the Chinese are interested in Rio Tinto's abundant iron ore production.

Here's why: China's purchase followed a stock-swap offer from BHP for Rio Tinto. The combination would rival Brazil's Vale (NYSE: RIO) for world supremacy in the production of iron ore, a key ingredient in the manufacture of steel, and one for which the Chinese appear to have an almost insatiable appetite. Thus far, BHP's second and latest proposal has received an icy reception from Rio Tinto.

So in a period that's not your father's market for all manner of commodities -- BHP predicted on Wednesday that prices for coking coal, another important ingredient in the manufacture of steel, could triple this year -- it appears that the Chinese are attempting to divide and conquer their major iron suppliers. By taking positions in both Rio Tinto and BHP Billiton, they'd be capable of playing a role in determining the direction of the iron ore market going forward.

From the perspective of Foolish investors, this series of events demonstrates the vital and growing importance of many metals in the world today. And so, while I've been admonishing Fools to include a solid energy representation in their portfolios, I'm also inclined to offer similar advice as it relates to metals and mining. All the companies named above are compelling in their own right, as is Phoenix-based copper giant Freeport-McMoRan (NYSE: FCX).

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