Ultrastructure of a Columbite-Tantalite Mineral from the Zhaojinggou Ta-Nb Deposit in the North China Craton: Direct Evidence of the Formation Mechanism of the Columbite-Group Minerals

Figure 6

(a) Focused ion beam-cut of the columbite-tantalite mineral. (b) High-magnification transmission electron microscopy image obtained from the green square in (a). (c) Selected area electron diffraction pattern obtained from the green square in (a). (d) High-resolution transmission electron microscopy image obtained from the green square in (a).