The term rare earths (RE) applies to a group of 17 chemically similar metal elements that include scandium, yttrium and the 15 lanthanides. RE elements are considered strategically important commodities - they are used to manufacture defense and commercial high value-added applications, not least in this environmentally conscious age, green technology. Rare earths were traded freely and at a discounted price on the global market before the mid-2000s. Since 2005, however, China - the world’s leading RE producer - has gradually tightened export restrictions on rare earth oxide (REO).