Abstract:

The authors report the results of study on the crystal habit and texture of vernadite in a co-rich crust from the Central Pacific Ocean using the JEM-6700F and JSM-2000FX. The results show that vernadites generally occur as a schistose singgle crystal, and schistose or scaly aggregates, and that the single schistose is 30-50 nm in size. The single and trilling crystals electron diffraction patterns of vernadites, i.e., d=0.142 9 nm, were obtained by JEM-2000FX.  Fe³⁺, Co³⁺, and Ni³⁺ exist in vernadite as high spin. Co³⁺, Ni³⁺, and Cu³⁺ are easy to substitute for Mn⁴⁺ in vernadite in a complete isomorphous form. Mn⁴⁺ is replaced by Fe³⁺ in a limited isomorphous pattern. The reaction is 3Mn⁴⁺=4Co³⁺(Ni³⁺、Cu³⁺、Fe³⁺), reaching the total electrovalent equilibrium in the system.

Key words: vernadite, crystal habit, electron diffraction pattern, isomorphous, co-rich nodule,  , Pacific Ocean