Home > Kalahari Manganese Field – March 18 > MS0905 Henritermierite

Henritermierite - Sold

Gaudefroy et al. (1969), named this mineral in honor of Henri François Émile Termier (1897-1989), Professor of Geology at the Sorbonne, Paris. Henritermierite is related to the garnet group minerals, however with lower tetragonal rather than cubic symmetry. The Mn3+ atoms distort the crystal structure, encouraging hydrogen bonding, leading to the ideal formula Ca3Mn2(SiO4)2(H4O4) (Armbruster et al. 2001). This specimen is a continuous druse of pseudo-octahedral henritermierite crystals, each averaging 1 mm on edge, and completely covering one face of the matrix. Also a curious psuedomorph appears on the side of the specimen. This is a large rich matrix example of a very rare garnet.