Searching for Rare Earth Minerals
Metals known as ‘rare earth elements” are in growing demand worldwide. They’re vital for many of the high tech devices we all use. China has been the major source for rare earth minerals, but recently cut its exports. This has geologists in the U.S. searching for domestic deposits.
If the term ‘rare earths’ is not familiar to you, the high tech devices that depend on them are. From the ear buds for your cell phone, to advanced medical devices like MRIs, and new technologies such as wind turbines, magnetic refrigeration and electric cars
“For example, we are using them right now because they make very good, very strong, small magnets so they are useful in microphones," says Neil Johnson, a geology professor at Virginia Tech.
"The elements themselves are actually not rare. They’re more common than gold or platinum, but the problem is that they’re rarely concentrated. "
And that often makes them difficult and expensive to mine. But the unique magnetic properties of rare earths, makes them seem almost magical. To demonstrate, Johnson first pulls some typical ceramic magnets out of his pocket and slowly moves them closer together.
“You hold them here and it will jump. Now the rare earth magnets, you can’t pull apart. What you have to do is slide them apart because they hold together so tightly."
Even then it’s not easy. They’re so powerful that you could be seriously injured if you caught your finger between them.
“And because these magnets are so incredibly strong for their size, they’re actually smaller than ceramic magnets so you can make electronics with very powerful magnets that are much, much tinier than other types of things.”
On a Saturday afternoon, Johnson is searching for rare earth minerals, not underground at the Roanoke Valley Gem and Mineral Society - Show in the Salem Civic. Her peruses rows of tables and glass showcases displaying eye catching geodes, glittering crystals and beautiful jewelry. Finally, he sets his sights on a humble looking small black stone
“What we have here is from the mountains in Pakistan. This is a sample of bastnasite. Now it will almost certainly have all of the other rare earths in it as well.”
It looks like something you ‘d pass on the street if you saw it, but not if you also saw the price tag, which reads two hundred dollars. And if even though it’s from Pakistan... “It will give us some of the data that we could use to see if thee are these types of deposits in the South East you start with a nice specimen so you know what to look for.”
If it checks out, Johnson will send the data to US Geological Survey Researcher, Nora Foley. Foley did her undergraduate and PhD at Virginia Tech and she’s now based in Reston, Virginia, where she’s leading the search for rare earths in the south east.
“The reason we’re looking at some sites in Virginia is because there’s a type of granite that occurs through out the Blue Ridge that tends to have relatively high amounts of all the rare earths in the granite itself.”
At a recent meeting of US Geological Survey held at Virginia Tech, Foley’s presentation started a buzz about the possibility of rare earths around here.
When those questions are answered, says Neil Johnson, the issue becomes, how do you go about mining it.
“And that is the gorilla on the horizon because any talk of drilling in the Southeast is going to receive some kind of push back.”
In part 2 of this report we’ll hear why scientists think the southeastern united states could become a source for the rare earth minerals that are in great demand all over the world, and what kind of concerns mining for them might raise.