The Rare Earth Element

 I was always excited about Rare Earth Elements. Below a short video is given to understand whatactually the rare earth elements? Please go through the video and checkout.
According to google / wiki rare earth element is:
  1. any of a group of chemically similar metallic elements comprising the lanthanide series and (usually) scandium and yttrium. They are not especially rare, but they tend to occur together in nature and are difficult to separate from one another.