Colorles to pale shades of olive-green crystal aggregates of magnesiotaaffeite-6N’3S in a specimen from a locality in Antarctica (Khmara Bay, Casey Bay, Enderby Land, Eastern Antarctica, Antarctica). Ex Vandenbroucke Museum collection from Waregem, Belgium — Photo: David Hospital · CC BY-SA 4.0
Magnesiotaaffeite-6N'3S
Magnesiotaaffeite-6N'3S is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Mg₂BeAl₆O₁₂.
It crystallizes in the hexagonal crystal system (space group R-3m). It is a member of the Taaffeite-Magnesiotaaffeite structural group.
Key properties: Mohs hardness 8–8.5; specific gravity 3.68; optically uniaxial.
IMA symbol Mtf- 6N'3S, IMA status: approved, named in 1966.
Found in a nodule, perhaps formerly a corundum crystal, in high-grade metapyroxenite, in association with metaperidotites and granulites (Musgrave Ranges, Australia); in pegmatite cutting granulite (Enderby Land, Antarctica).
It is found associated with Spinel, sapphirine, phlogopite (Musgrave Ranges, Australia); quartz, sillimanite, garnet, biotite, surinamite, sapphirine (Enderby Land, Antarctica).
The name refers to the Musgrave Ranges, South Australia, from where it was first recognized.