XRF Exposes Counterfeit “14K” Gold
The bracelet below, marked “14K”, is in fact, not 14K gold. Analysis by XRF reveals it has <1% gold and is consistent with a gold-plated base metal containing primarily copper, possibly a nickel-plated brass which is then coated with gold. A blowup of the spectrum shows the emission lines for the trace of gold barely above the baseline. Although XRF is considered a “surface” analysis, it can see below the surface to some extent, depending on the material (See Heterogeneous Materials).
