Garnet

Mn₄O₁₂Si₄

Fujino, K.Momoi, H.Sawamoto, H.Kumazawa, M.

American Mineralogist (1986) 71, 781-785

a=11.774Å   b=11.774Å   c=11.636Å

α=90°   β=90°   γ=90°