A yellow or brown sofa would be an earth element.

Separation of the rare earth elements is a step in the later processing.

China was already a world leader in certain areas such as rare earth elements.

Finding rare earth elements is only the first and some argue the easiest step.

In the original draft of the book I had three chapters on the rare earth elements.

Dark colors form the earth element or lower level.

Is the domestic production of rare earth elements essential to American economic and national security interests?

However, most rare earth elements are not found in concentrated or pure forms.

The Lanthanides (also called the rare earth elements) are part of this period.

Later he became involved in the research of the rare earth elements.