Neodymium(III) sulfate

Neodymium(III) sulfate is a salt of the rare earth metal neodymium when mixed with sulfuric acid. Its octahydrate forms violet-red crystals. It is moderately soluble in water and has a monoclinic crystal structure. It can be used to treat water but because of its rarity, it is not used that way. 
Preparation.
Neodymium sulfate is produced by dissolving neodymium metal in sulfuric acid.
Uses.
It is used in glass for extremely powerful lasers. It can be used to treat water but is not used because of its rarity.