The world’s most valuable copper deposits, known as porphyry deposits, originate from cooling magma. But how can we predict the size of these deposits? What factors govern the amount of copper present? Researchers at the University of Geneva (UNIGE), Switzerland, have studied over 100,000 combinations to establish the depth and number of years required for magma to produce a given amount of copper. The same scientists have also devised a model that can detect the quantity of copper held in a deposit by means of a simple factor analysis. The research, which is published in the journal Scientific Reports, will make it possible to estimate the potential for mining the metal before beginning any drilling. It is a model that will undoubtedly be of great benefit to mining companies.