Several analytical methods are used to test gold and other precious metals’ purity and authenticity, including acid scratch tests, conductivity measurement, and X-ray fluorescence (XRF ...

Electronic gold testers are fairly accurate when used properly (they must be fully cleaned of the gel in between uses). The most accurate tests use X-ray fluorescence spectrometers (XRF).

SPECTRO Analytical Instruments has expanded the capabilities of its SPECTRO xSORT handheld XRF analyzer — designed for rapid ... environmental screening, and compliance testing. Geology and Mining: ...