Beryllon II is a specialty chemical primarily used as a colorimetric reagent in analytical chemistry for the detection and determination of beryllium ions in various samples, such as water, soil, and industrial materials. It forms a distinct red-colored complex with beryllium, enabling precise quantification through spectrophotometric methods. This application is particularly valuable in environmental monitoring, assessing beryllium contamination in industrial processes, and research laboratories studying beryllium's chemical behavior and interactions. Its high sensitivity and selectivity ensure accurate measurements in analytical procedures.