Earlier quoted context omitted.
I wonder how much rare earth material will get incinerated over the next few decades with thousands of these things burning up annually. Hope we figure out space mining quick.
Rare earth elements actually aren't that rare. For example, neodymium makes up over 30 ppm of Earth's crust. That's more common than lead, cobalt, tin, thorium, tungsten, molybdenum, and quite a few other elements with large-scale industrial applications. The difficult part of producing rare-earth elements is separating them from everything else. Tiny pieces of spacecraft dust scattered over a large area don't make v…
Rare earth elements are so named because their earths are rare: there aren't many places on the crust where their concentration is significantly above the average. Mining depends on the existence of mineral earths.
GP raises a valid point -- although a weak one.