Growing public interest in getting information on the origin of raw materials used to manufacture goods for daily life has triggered the development of concepts to increase the transparency of raw material supply chains. Analytical proofs of origin (APOs) for raw materials may support those transparency concepts by giving evidence about the origin of a specific raw material shipment. For a variety of raw materials like gemstones, TTT (tantalum, tin, tungsten) minerals, and others, APOs have been developed. The identification of features that distinguish different origins, databases of those features from reliable reference samples, and a data evaluation strategy adopted to the envisaged application scenario are the key aspects of APO methods. Here, an overview is given on APO methods developed for different raw materials and application cases.

Raw material supply chains are complex systems. They build on the presence of economically mineable mineral commodities that will undergo several steps until they are finally being used as consumer products. Trustworthiness into the transparency of a supply chain is of increasing importance, both to upstream and downstream companies. Any deviation from best-practice and quality standards in mining, processing and production is critically looked at by consumers. Therefore, certification systems and proof of origin concepts have emerged within the past years, aiming at providing transparency to supply chains. The analytical proof of origin for mineral raw materials could be beneficial to certification schemes in several ways. It represents the least corruptible method of provenance analysis as it relates directly to the chemical composition of the raw material. Other methods, such as documents, tracers, or barcodes, can be outmanoeuvred in one way or another.