Validity of “off-the-shelf” handheld portable XRF for sourcing Near Eastern obsidian chip debris

► Handheld portable XRF (HHpXRF) has been met with debate and scepticism. ► Archaeological interpretations in HHpXRF-based studies are cast into doubt. ► Validity of HHpXRF was tested under deliberately “sub-optimal” conditions. ► Irregular debitage near size limits analysed using “off-the-shelf” calibrations. ► Sourcing success rate of 94% (A-rank matches) to 100% (A- and B-rank matches).