Rare earths

Rarth elements or rare earth metalsare a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides plus scandium and yttrium.[2] Scandium and yttrium are considered rare earth elements since they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties.

Despite their name, rare earth elements (with the exception of the radioactive promethium) are relatively plentiful in the Earth's crust, with cerium being the 25th most abundant element at 68 parts per million (similar to copper). However, because of their geochemical properties, rare earth elements are typically dispersed and not often found in concentrated and economically exploitable forms. The few economically exploitable deposits are known as rare earth minerals.[3] It was the very scarcity of these minerals (previously called "earths") that led to the term "rare earth". The first such mineral discovered was gadolinite, a compound of cerium, yttrium, iron, silicon and other elements. This mineral was extracted from a mine in the village of Ytterby in Sweden (Earth)

Virtually every technologial product of modern Union society needs Rare Earth minerals. Thus mining and trade of these materials are very important and highly profitable.

'''Little Plastic Sacks filled with a set weight (or pressed into coins and coated with plastic) of Terbium or Samarium are a readily accepted form of payment everywhere in the known Universe. '''