[2][7] Later investigations showed that zemannite, as well as the related mineral kinichilite, often contains impurities of sodium and magnesium and thus the formula was refined to its current form, Mg0.5ZnFe3+[TeO3]3·4.5H2O.

As a result of this process, the elemental tellurium or tellurium-anions (Te2− or Te22−) transform into the Te4+ cation bound with oxygen into the tellurate ion [TeO3]2−.

[9] In addition to Moctezuma, zemannite was also found in Vielsalm – a municipality in the Belgian province of Luxembourg and near Shimoda, Shizuoka, Japan.

These tellurium-oxygen and Fe/Zn-oxygen polyhedra form a network with wide (0.83 nm diameter) channels parallel to the crystallographic c axis (normal to the picture).

[2][7] The Mg2+ cations form octahedral Mg[(H2O)6]2+ complexes with six water molecules which are located in the channels of the crystal structure.