“3D printing companies are the new Rare Earths.”

Thus spake Twitter, a few hundred-million Tweets ago, giving birth to the new meme on what matters most in our constantly-evolving technology world. Meaning, of course, that the furor over Rare Earths sparked three years back — when China used its then-97% production monopoly as a weapon against REE-dependent Japan — has run its course.

The new shiny object in the tech world: 3D printing.

But dig deeper (at ARPN, the pun is always intended), and the story gets more complex. Technical papers — like this one from Germany’s Munster University — are reporting that one of the best materials for the 3D printing process are compounds like Nano-Yttria and Lutetium-Aluminum Garnet. From the literature, it seems that these compounds excel as “ligands” — binding agents in the 3D printing process.

Which means that the next new thing — 3D printing — will require plenty of the “last new thing” — Rare Earths.

That’s a useful corrective to the commentators who routinely claim that manufacturers will find ways to substitute around Rare Earth Elements. Of course, in many cases, they will. And in just as many instances, other researchers will find new applications for Rare Earths.

Meanwhile, China’s production monopoly has shrunk — from 97% in 2010 to 95% today.

As the fashion industry well knows, sometimes “the new black” is… black. 3D printing is a truly revolutionary concept destined to transform the process of manufacturing. But to the extent that 3D will require specific Rare Earths in the manufacturing process, the Rare Earths are still “the next Rare Earths.”

And unless the industrialized democracies want to see 3D printing become the new engine of China’s economy, someone needs to make the actual mining of critical metals and minerals “the next new thing.”