Evolution of the Fe/Mn ratios of cassiterite from pegmatites of the FA field in function of selected trace element ratios and concentrations (based on ppm contents from LA-ICP-MS analyses). Composition trends for petalite- and Li-mica-rich pegmatites in possible relation with the vertical distance of migration of their parent magma are shown as arrows in (b). Compositions of early, low-CL, and late, high-CL, cassiterite from the Bajoca pegmatite are distinguished.