A Nebraska mine formed to extract a rare heat-resistant element from the earth has been found to also contain a sizable deposit of Rare Earth Elements. NioCorp Developments announced the latest analysis where it plans to build a mine, about 80 miles south of Omaha near the town of Elk Creek, shows the deposit of rare earth elements found is the second-largest in the United States. Estimates based on the analysis are that there are 632.9 kilotons of rare earth elements available for extraction.

The data is still being reviewed to see if it will be profitable to extract those elements in addition to the niobium, scandium and titanium the mine is going to produce.

NioCorp still has to raise $1 billion to build the mine above the more than $60 million it has already invested in exploration and development at the site.