I hope all of you Irregulars are having a delightful Friday — here in the nation’s capital it’s raining (actual precipitation, not just the cash coming down from Ben Bernanke’s helicopters) and grey, and your friendly neighborhood Gumshoe needs a bit of a pick me up.

So what fits the bill for today’s Friday File? How about another sexy teaser about a rare commodity that has strategic importance, that China will be buying, and that’s mined in the US? And no, it’s not rare earth minerals or cobalt, though we’ve also seen many a teaser for both of those lately, too.

The ad comes in from Andrew Snyder for his TFN Strategic Trader newsletter, and this is how it begins:

“China wants its money back… any way it can!

“— This could be the largest transfer of wealth in modern history —

“This is your chance to rack up 1,389% gains from the ‘COMMODITY CARRY TRADE!'”

So you can already tell that they’re playing off Tim Geithner’s trip to China (and the fact that the Chinese students laughed at his assurances of the safety of their dollar holdings), and the recent moves by China to begin, albeit gradually, diversifying away from the dollar.

They do this in many ways, of course — baskets of currencies and gold are the main reserves they seem to be switching to … but they’re also spending some of their reserves, not just to stimulate their economy at home but to buy up natural resource caches around the world. Not everyone loves this, as seen by Rio Tinto’s turned back to Chinalco just today, but it seems unlikely to stop in the near term.

Here’s how Snyder pitches the scenario:

“China is fed up and rightfully scared it’s going to lose its money.

“This notion has launched the start of the “Commodity Carry Trade”, or CCT for short. It’s one of the largest wealth-exchange mechanisms in history.

“The CCT doesn’t involve gold. The CCT has nothing to do with silver. And forget what you heard about copper. The CCT is about something even bigger, even more economically important.

“The metal that the smart traders are buying is central to China’s long-term wealth. It’s the keystone of the CCT.

“Let me take a minute to fill you in on the details…

“Every time America has a deficit it needs to finance (about twice a ...