Drilling is set to resume in southeast Nebraska this week as a Canadian mining firm looks for more evidence of a sizable deposit of a valuable and rare heat-resistant element used in steel.

NioCorp Developments said Tuesday it has hired West-Core Drilling of Elko, Nevada, to collect more core samples from the niobium deposit near Elk Creek.

This summer's drilling will be the first since 2011 at the site. The company is trying to determine whether it would be profitable to build a mine to harvest the niobium from several hundred feet underground.

The U.S. currently imports nearly all the niobium that's used in this country to harden steel and make it more heat-resistant for industrial uses.