Rhenium in molybdenite: A database approach to identifying geochemical controls on the distribution of a critical element

Rhenium (Re) is one of the rarest elements on earth and is a designated critical element in the United States and European Union for its uses in superalloys. Unusually among critical elements, Re is produced entirely as a byproduct of molybdenite (MoS2) mining, as pure Re minerals are extremely rare. However, Re concentration in natural molybdenites varies from a few parts per trillion to tens of percent. There are few known consistent patterns and no firmly established reason for this variation, making it difficult to use molybdenite Re content as a proxy for metal grades, a vector to high grades, a clue to the geological and geochemical nature of the ore deposit, a guide to overall Re resources or for any other of the applications that have been suggested for it over time.