Rare Earth Elements (‘REE’) are non-toxic elements essential to a cleaner environment and reduced reliance on fossil fuels. Also, REE are an enormous potential benefits to human health.
There are 16 REE in total, as defined by the U.S. Geological Survey, 15 lanthanide elements appearing at the bottom on the Periodic Table, with atomic numbers ranging from lanthanum (57) to lutetium (71), plus the metal yttrium (39); all of which display similar physical and chemical properties. REE deposits tend to occur in two sub-groups:
Yttrium (Y) most commonly occur in association with HREE sub-group
REE are not particularly rare; similar abundance in the earth’s crust to nickel or tin, but generally not concentrated in commercial ore deposits.
COMMON PROPERTIES OF RARE EARTHS
Prices for REE's differ a lot. To give you an idea, look at the next overview which was on the Quest Uranium site:
Current prices can be found
The next chart shows clearly how the price for REE's went up the last few years.