Formula
(repeating unit) Ca2NaMg2[VO4]3 Crystal system Cubic | Strunz classification 8.AC.25 Space group Ia3d | |
Category Phosphate mineral
Berzeliite group
Garnet structural group Crystal class Hexoctahedral (m3m)
H-M symbol: (4/m 3 2/m) | ||
Schäferite is a rare vanadate mineral with chemical formula Ca2NaMg2[VO4]3. Schäferite is isometric, which means that it has three axes of equal length and 90° angles between the axes. Schäferite is isotropic, meaning that the velocity of light is the same no matter which direction the light passes through.
It was named after Helmut Schäfer (born 1931) who discovered it in a quarry on the Bellerberg volcano in Germany. It is found only in the Eifel Mountains volcanic area near Mayen, Laacher See district of Germany. It occurs within a xenolith in a leucite tephrite. It is the magnesium analogue of palenzonaite and is a member of the garnet structural group.
References
Schäferite Wikipedia(Text) CC BY-SA