About rare earth elements

The unique chemical and physical properties of rare earth elements (“REEs”) have positioned them as critical materials across several rapidly evolving markets and industrial applications. Used extensively in high-technology applications ranging from mobile telephones and televisions to LED lighting, they are also fundamental elements in low carbon technology such as electric vehicles (“EVs”) and wind turbines owing to their role in permanent magnets.

Comprising 17 unique chemical elements, REEs are often separated into two sub-groups based on atomic weight:

  • light REEs (Lanthanum, Cerium, Praseodymium, Neodymium and Samarium), which are more abundant; and
  • heavy REEs (Europium, Gadolinium, Terbium, Holmium, Erbium, Thulium, Ytterbium, Lutetium as well as Scandium and Yttrium), which tend to be rarer.

Whilst rare earths are not actually that scarce within the Earth’s surface, they are rarely concentrated into mineable ore deposits and are often not economically viable to extract. They also co-exist within the same orebody, creating complications from a separation and processing perspective. Economic sources of REEs are principally found within the minerals bastnasite, monazite, and loparite and lateritic ion-adsorption clays.

Some REE minerals contain significant amounts of radioactive elements such as uranium and thorium, which have the potential to contaminate air, water, soil and groundwater. However, Rainbow’s projects demonstrate low levels of radioactive elements, an important factor that we believe sets the Company apart when compared to many typical rare earth development projects.