The US Department of the Interior published the list on Friday after president Donald Trump called for a critical mineral strategy at the end of 2017.
NioCorp said the Elk Creek Superalloy Materials project was one of the few polymetallic greenfield mining projects in the US that proposed to produce multiple critical minerals - namely niobium, scandium and titanium.
It said the Elk Creek ore body was also known to be "enriched in rare earth elements" although it currently had no plans to produce rare earth commercial products.
Its shares closed up C13c to 65c, although it remains down a little more than 12% year-to-date.
More broadly, Toronto's S&P/TSX Composite Index metals and mining sector closed up 0.32% on Friday.
The gold sector mainly enjoyed a positive finish to the week, led by Torex Gold Resources (TSX: TXG) up 3.9% and Sandstorm Gold (TSX: SSL) up 3.17%).
Gold remained near a five-month low on the spot market earlier today, just below $1,290 an ounce.
However in Australia, the gold sector started this week on positive note, up 1.34% on the benchmark S&P/ASX200 index in morning trade with Newcrest Mining (ASX: NCM) up close to 1.7%.