Spessartine

• Named after its type locality Spessart (Bavaria, Germany)
• Formula: Mn₃Al₂[SiO₄]₃
• Space group: Ia-3d (No. 230)
• Crystal system: cubic
• Crystal class: m-3m
• Lattice parameters: a = b = c = 11.621 Å, α = β = γ = 90°

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Picture: Rob Lavinsky – iRocks.com  | CC BY-SA-3.0

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Crystal structure (click on the picture 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).)

• MnO₈ polyhedra (purple)
• AlO₆ octahedra (blue)
• SiO₄ tetrahedra (orange)

For a 3D interactive version on sketchfab, see here:

https://skfb.ly/6BQQP

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