[whatio]

“Rare” is being used in the same sense as “rare earth elements,” not in the typical, common usage of rare. The “rare” part comes from:

1. They rarely form concentrated ore deposits, instead being widely dispersed throughout rock formations

2. The elements are very chemically similar to each other, making them difficult and expensive to separate and purify for industrial use

[_2d30]

[flagged]

[dang]

Please make your substantive points without breaking the site guidelines.

Your comment would be fine with just the second sentence.

https://news.ycombinator.com/newsguidelines.html

[MiguelX413]

Or the headline