Phosphorus is a unique element. It is the limiting nutrient controlling biological productivity in many terrestrial and marine environments. When in excess, however, dissolved phosphate leads to uncontrollable biological growth and water-quality problems through a process called eutrophication. The use of phosphate minerals and their products as fertilizers has increased tremendously global food production; it would not be possible to feed the current world population without phosphate fertilizers. Yet phosphate is a limited global resource; current estimates suggest economic phosphorus supply may be severely depleted over the next 100 years. Nevertheless, mineralogists and geochemists have invested little time investigating phosphate mineral stability, reactivity, and transformations. This issue attempts to bring phosphates to the forefront of our scientific endeavours.