Rincon Resources (ASX:RCR) has announced its possible discovery of niobium and rare earth element (REE) mineralisation at its Avalon and Sheoak targets. Both niobium and REE mineralisation was detected by a hand-held pXRF machine “associated with syenite intrusions” at both areas of interest. “Some elevated REE elements were detected,” the company wrote on Monday. Full fledged assays are on the way with samples from recent drilling either in Perth or en route to assay labs. A batch of samples pulled from an RC drill run are at the capital while diamond drill hole samples are in tow. The compan…