It's a pretty sizable deposit, but it's underground. That means it'll be pricier to extract, and not all of the ore can be mined. Looks like lower grade than the Chinese deposits currently mined too, and it's a different mix of elements.

http://www.quantumrareearth.com/projects.html

http://www.iamgold.com/English/Operations/Operating-Mines/Ni... - a similar deposit in Quebec.

http://pubs.usgs.gov/fs/2002/fs087-02/fs087-02.pdf - good summary of REEs