Tuhualite Locality: Opo Bay (South East Bay), Mayor Island (Tuhua), New Zealand Purple/dark blue xls of Tuhualite. Field of view 3 mm. Specimen was collected by Volker Hoppe at Mayor Island in oktober 2001. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Tuhualite
Tuhualite is an IMA-recognized mineral species in the silicate class, with the chemical formula NaFe²⁺Fe³⁺Si₆O₁₅.
It crystallizes in the orthorhombic crystal system (space group Cmca).
Key properties: Mohs hardness 3–4; specific gravity 2.89; optically biaxial.
IMA symbol Tuh, grandfathered status — known before the IMA’s founding, named in 1932.
A primary igneous mineral and in vesicles of some silicic lavas, as comendites and pantellerites.
It is found associated with Alkalic feldspar, quartz, aegirine, riebeckite, aenigmatite, arfvedsonite.
The name is taken from the type locality, Mayor Island, New Zealand, which is called Tuhua by the native Maori.