Author name: John F. Rakovan

Apatite has numerous applications that benefit society. The atomic arrangement of the apatite crystal structure and its rich and variable chemistry impart unique properties, which permit a wide range of technological and scientific applications in an array of disciplines outside of the traditional Earth sciences, including ecology, agronomy, biology, medicine, archeology, environmental remediation, and materials science. In our daily lives, apatite is essential for sustaining and enhancing human life through agricultural amendments, through bone replacements, through fluorescent lights, and through environmental remediation of contaminated soils. Apatite is truly a technological gem.

Apatite is ubiquitous in igneous, metamorphic, and sedimentary rocks and is significant to more field of study than perhaps any other mineral. To help understand why, one needs to know apatite’s structure, composition, and crystal chemistry. Apatite has a robust hexagonal atomic framework based on two distinct metal-cation sites (M1, M2), a tetrahedral-cation site (T), and an anion column along four edges of the unit cell. These cation and anion sites can, among them, incorporate more than half of the long-lived elements in the periodic table, giving rise to the “apatite supergroup,” which contains over 40 mineral species. The structure and composition impart properties that can be technologically, medically, and geologically very useful.