The two primary technologies are X-Ray Fluorescence (XRF) and Ultrasonic Testing. XRF analyzers are the industry standard for non-destructive surface analysis, providing a full elemental breakdown (gold, silver, copper, platinum) in seconds. For deep-core analysis to detect tungsten inserts inside gold bars, Ultrasonic thickness gauges or Electrical Conductivity meters are recommended. For high-precision B2B transactions, prioritize XRF spectrometers with Silicon Drift Detectors (SDD) as they offer higher resolution than standard PIN diode detectors.