Chemical composition of columbite-group minerals from pegmatites of the FA field. Filled and empty symbols represent data from this study and the literature (Roda-Robles et al., 1999; Vieira 2010), respectively. (a) Ta/(Nb+Ta) versus Mn/(Mn+Fe) diagram (apfu) with tantalite-tapiolite miscibility gap from Van Lichtervelde et al. (2018). Evolution trends of CGM compositions interpreted as reflecting, either magma differentiation at the scale of the pegmatite field, or internal evolution after pegmatite-forming magma emplacement, including late-magmatic to magmatic-hydrothermal processes, are indicated. CGM crystal rims or mantles as well as CGM in inclusions in cassiterite (see Figs. 9 and 10) are distinguished with a white and red dot, respectively. (b) Sn versus Ti diagram (apfu).