Regulus su8230

The surface morphology and elements of the calcite were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) (Regulus SU8230, Hitachi, Tokyo, Japan). The resin A glue and B glue were mixed with a mass ratio of 3:1, stirred for 5 min to obtain transparent mixed resin glue, the flake calcite sample (5 × 5 × 3 mm) was placed in a silica gel mold with a diameter of 1.0 cm, and then the resin glue was poured and allowed to stand for 24 h to obtain the glued calcite sample. Then, 200, 800, 1500, 3000, and 5000 mesh silicon carbide sandpaper were used to polish the glued calcite sample surface. The samples were then processed with 3 mol/L sulfuric acid, reacting for 5 min. After that, the mineral samples were coated with gold using a sputter coater after being dried in a vacuum oven at 40 °C. Finally, the processed samples were examined using a Phenom (Ambler, PA, USA) ProX equipment at a 10 kV accelerating voltage.

Field emission SEM (FE-SEM) was used to obtain the surface topology (Hitachi Regulus SU8230). The samples were placed on the microscope holder and adhered to a carbon tape. It was then loaded into the FE-SEM chamber, with a working distance of 3.8 mm, an accelerating voltage of 15 kV, and an emission current of 700 nA. The reading from secondary electron detectors was then used to obtain the topological information.