The straczekite group includes: bokite: (Al,Fe)1.3(V5+,V4+,Fe3+)8O20.7.5H2O corvusite: (Na,Ca,K)1-x(V5+,V4+,Fe2+)8O20.4H2O straczekite: (Ca,K,Ba)(V5+,V4+)8O20.3H2O Back to Minerals