Portable XRF analyzers are being utilized by a variety of organizations, including geological surveys, universities, and explorers. They are commonly used as a pathfinder tool to identify areas of interest that then undergo more rigorous laboratory analysis. For example, the British Geological Survey uses three portable XRF instruments to support their work. Exploration companies in Tanzania and Nigeria have employed them to guide rare earth and rare metal projects. Meanwhile, organizations in the UK and Iran have applied them to platinum and lead-zinc exploration. What makes portable XRF analyzers so useful is their ability to provide a basic chemical fingerprint of samples in just a few minutes without any sample preparation. Elements from magnesium to uranium can be detected, although heavier rare earths can be challenging. This allows rapid, cost-effective screening of drill core, rock chips, soils, and other materials directly in the field. One case study estimated savings of over $1 million in assay costs in just 12 months for a mining company using portable XRF TrueX G5/ TrueX G7. However, there are limitations to consider. Detection limits may not reach parts-per-million levels achievable by laboratory techniques. Elemental results can be affected by variations in sample composition, such as differences between oxides, sulfides, and carbonates. Further, spectral interferences can occur where peaks for different elements overlap on the analyzer. Proper sample preparation is also important given the 1cm XRF window size. For portable XRF data to be reliable and trustworthy, it is crucial best practices are followed. Regular instrument calibration using certified reference materials is needed to confirm accuracy. Quality control using standards and duplicate samples should be incorporated into all sampling protocols. Methodologies must be customized to the required accuracy - while semi-quantitative data may suffice for early exploration, higher precision is demanded for grade control. Thorough training and competency of all operators is essential to maximize portable XRF potential and avoid costly mistakes. It is telling that the new JORC Code specifically references portable XRF usage, reflecting its increasing importance. But to fulfill reporting requirements, details must be disclosed about sampling and protocol methodology, as well as any limitations of the portable data. One example saw an exploration company wrongly report significant gold in an announcement based on erroneous portable XRF results, only to retract it later. Proper implementation and management of portable XRF data is required to build confidence in the results. In conclusion, a portable XRF analyzer is a highly useful exploration tool when deployed correctly. But various human, technical, and limitations must be well understood. Adopting comprehensive and standardized methodologies tailored to each project's needs ensures portable XRF data is fit-for-purpose and its full value can be reliably leveraged by the mining and exploration sector.