Zemannite

• Named in honor of the Austrian mineralogist Josef Zemann (born 1923 and died just three weaks ago on the 16th of October 2022 at the age of 99), who had worked extensively on tellurium minerals. An obituary on Zemann in German can be found here.
• Type Locality: The Mina La Bomballa near Moctezuma, Sonora, Mexico
• Formula: Mg_0.5ZnFe³⁺[TeO₃]₃ · 4.5 H₂O
• Space group: P6₃/m
• Crystal system: hexagonal
• Crystal class: 6/m
• Lattice parameters: a = b =  9.41 Å, c = 7.64 Å, α = β = 90°, γ =  120°

Picture: Christian Rewitzer – CC BY-SA 3.0

Crystal structure (click on the pictures to download the VESTA file):

(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,” J. Appl. Crystallogr., 44, 1272-1276 (2011).)

• Fe/ZnO₆ octahedra (green)
• TeO₃ trigonal-pyramids (blue)
• MgO_x polyhedra (orange)
• Oxygen (red)
• Hydrogen (white)

For a 3D interactive version, see here:

https://skfb.ly/ozQXK

Refs.:

[1] J.A. Mandarino, E. Matzat, S. J. Wiliams, Zemannite, a zinc tellurite from Moctezuma, Sonora, Mexico.Canadian Mineralogist 1976, 14, 387–390.

[2] R. Miletich, Crystal chemistry of the microporous tellurite minerals zemannite and kinichilite, Mg_0.5 [(Me²⁺Fe³⁺) (TeO₃)₃] · 4.5 H₂O, (Me²⁺ = Zn, Mn). European Journal of Mineralogy 1995, 7, 509–523.