4 ms·
> "point is that they're rare..." They are not, in fact, rare, as is almost always pointed out when they are mentioned.
by moloch-hai 4y ago
> "point is that they're rare..."
They are not, in fact, rare, as is almost always pointed out when they are mentioned.
- culi 4y ago> Because of their geochemical properties, rare-earth elements are typically dispersed and not often found concentrated in rare-earth minerals. Consequently, economically exploitable ore deposits are sparse (i.e. "rare"). Regardless, they never show up in a pure form in nature so what we should really be looking at is how common minerals that they're easy to extract from are not how common the atom itself is. And the useful rare-earth minerals are indeed "rare"
- moloch-hai 4y agoVanishingly few things show up in "pure form", anywhere in nature. Gold is is all mixed up into quartz, save for flakes in riverbeds. Nitrogen and argon, famously unreactive, nonetheless come mixed with the other, with oxygen mixed in besides. Diamond, almost pure carbon, is the only that comes to mind. So, it is meaningless to single out lanthanides for this. What does distinguish them, instead, is that they are expensive to separate from one another. In certain places such as Yterby and the site mentioned in the original article, ore contains a concentrated mix of many lanthanide compounds. It remains a chore to get the praseodymium and the neodymium into separate ingots.