The fifteen REE can be grouped into light and heavy lanthanides. The light REE are lanthanum, cerium, praseodymium, neodymium, promethium, samarium and europium. The heavy REE are gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. Scandium and yttrium are not true REE but are often categorized as such since they are often co-located and have similar properties.
The production of many clean-energy products relies upon the availability of heavy REE (HREE), typically available in reduced concentration in most mineral deposits. Canadian mineral endowment combined with world-renowned geological and metallurgical expertise would suggest that there is a strong potential for Canada to be an important global supplier of HREE in the near future.
Over the past 15 years, research and knowledge have evolved regarding the characteristics and uses of rare earth elements such that many of these materials have become indispensible in the manufacture of advanced technological equipment with a particular focus on clean-energy applications such as wind turbines and hybrid/electric cars. Most consumer electronic devices require REE and new technologies being developed for water purification, desalination, magnetic refrigeration, and more energy-efficient light bulbs will need REE as well.
Although Canada does not currently produce significant amounts of REE, it relies upon the import of REE-containing components for the manufacture of key products in many industries. Thus, while the sector directly involved in REE was worth about US$1.25 billion in 2009, its indirect value throughout the global economy may be measured in trillions of dollars.