Rare earth elements (REE) are a group of 17 metallic elements comprising lanthanides (elements from lanthanum to lutetium), yttrium and scandium. REE mineral occurrences are spread worldwide in various geological environments, however, explored minable deposits are less common. Economically significant quantities of REE have been currently extracted in just a few countries situated outside Europe, and the European industrial and technological sector depends strongly on REE imports. A growing demand for REE in many industrial branches put REE on the list of Critical Raw Materials (EC Communications 2011 & 2014), thus giving a perspective for research on European REE resources.