By some estimates, the sum total of gold mined from the time of the ancient Egyptians through today would fit neatly into a 25-meter cube. That makes it pretty scarce.

But for every 10 ounces of gold dug up from the ground, miners extract less than 1 ounce of platinum.

And these precious metals are downright plentiful compared to promethium, a trace element that comprises just four parts per quintillion in naturally occurring ores. The entire global supply is thought to be a mere 500 grams — about the weight of a football.

Promethium is the rarest of the “rare earth metals,” a series of 17 obscure elements with unusual properties and valuable commercial applications. These metals aren’t exactly household names just yet. You might not even be able to pronounce ytterbium, let alone know what it’s used for.

But if the combination of tight supplies and booming global demand intrigues you, then you’ll want to take a few minutes to familiarize yourself with this group. Because even after posting red-hot gains of 100% or more during the past year, stocks in this sector still have untold upside potential.

Demand will boom from here
The term “rare earth metals” is something of a misnomer. Some of these metals are as common as copper or nickel in the earth’s crust. But they’re highly dispersed and seldom found in concentrations high enough to be economically mined; oxides must be stripped from the ore, refined and then converted into useful alloys.

Yet all our technological gadgets demand these metals. They’re in everything from computer hard drives to lasers to MRI machines to weapons guidance systems, and hybrid and electric vehicles. Our cell phones and Kindles and iPads all require them as well.

Given their irreplaceable metallurgical, optical, magnetic and chemical properties, manufacturers throughout Asia, Europe and North America are desperate to get their hands on rare earth materials.

But you can’t just pop into the nearest Wal-Mart for metals like neodymium. There is really only one source at the moment — and it’s turning customers away left and right.

Rapidly shrinking supply — for now
Until the mid 1980s, the United States was largely self-sufficient and could meet its own rare earth metals needs. But in the past two decades, the global balance of power has shifted dramatically. China has been able to undercut prices and force other producers out of business. In fact, China’s predatory pricing policies closed so many mines that today the country enjoys a near monopoly.

Now, China controls 97% of the rare earth market — and up to 99% of the production of dysprosium, arguably the group’s most critical and hotly demanded metal.

Yet global consumption keeps rising. And China’s supply restrictions have pushed prices sharply higher. Neodymium oxide has more than doubled in the past four months alone. Others have spiked as much as tenfold.

All of this presents a unique opportunity for investors. Prices are soaring. And while China may produce 97% of all rare earth oxides, that’s not because China has a resource monopoly — it just happens to have almost all of the world’s operating rare mines.

As you can see below, more than half the world’s deposits are outside of China. So there are plenty of rare earth oxides — we just need to mine them.
My top rare earth metal play is doing just that. It operates a prolific mine in California.

Last quarter, it sold 1.2 million pounds of oxides, up from 800,000 a year before. Better still, the average sales price has tripled from $2.45 per pound to $7.31. As a result, revenue skyrocketed 329%.

Out of respect to my Scarcity & Real Wealth subscribers, I can’t dole out more of my research here, but you can learn a little more about the company in my webcast (I discuss rare earth metals just after the section detailing the global demand for uranium). Click here to watch now.

Action to Take –> But the easiest way to buy into rare earth metals is with the Market Vectors Rare Earth/Strategic Metals (NYSE: REMX). It’s an exchange-traded fund (ETF) that holds about 25 different rare earth companies.

On the plus side, it offers direct access to many of the biggest players around the world. However, its diversification also means it lags some individual plays. For instance, the company I mentioned above has tripled REMX’s performance in the past six months.