Resolution Minerals (ASX:RML) produced concentrates of 52.3% tungsten trioxide via preliminary gravity separation test work on tungsten composite samples, assaying 1.85% grade of tungsten trioxide, from stockpiles at the Johnson Creek mill site, sourced from the historical mining at the Golden Gate tungsten mine in Idaho, according to a Tuesday Australian bourse filing.

Heavy liquid separation scoping tests on the tungsten composite samples achieved a grade of 52.3% of tungsten trioxide with a recovery of 75.5%.

Its shares rose 4% in recent trading on Tuesday.