97% Correlation of Photon and Fire Analysis ResultsThe new Chrysos TM PhotonAssay Max technology uses high-energy X-rays to directly measure gold in bulk ore samples, combined with fully robotic sample handling to keep up with the high demands of the mining industry. Testing on a large suite of certified reference materials demonstrates that accurate gold values can be determined over a wide range of concentrations, with a detection limit down to 0.03 ppm. PhotonAssay is a non-destructive technique that does not require gold to be liberated from gangue material before analysis, meaning that samples can be prepared with larger particle sizes, reducing losses of gold that can occur through smearing onto the surface of pulverising equipment. Through analysis of suites of material from drill sites across Australia, we have found that results determined by PhotonAssay on drill core and reverse circulation drilling samples crushed to a top-size of 2-3 mm generally correlate at a level of 97% or better with traditional fire assay values. For sites with particularly coarse gold, it is advantageous to further reduce the particle size before sampling for assay, but the much larger PhotonAssay sample size (400-500 g approximately) significantly reduces sampling errors compared to traditional 25-50 g fire-assay. Statistical tests show that results from fire-assay and PhotonAssay can be used interchangeably during a drilling program. We present detailed results from several case studies to illustrate these findings. The combination of simplified sample preparation and reduced sampling errors are of immediate benefit to geologists responsible for resource definition and grade control analyses. Significantly reduced turnaround times, lowered staffing requirements and the removal of the use of toxic reagents, such as lead, are additional benefits offered by the new technology.