This is a hydrous Fe-bearing wadsleyite sample under a polarized microscope — Photo: Zwymmmm · CC BY-SA 4.0
Wadsleyite
The β-phase of olivine — the mineral thought to hold water deep in Earth's mantle transition zone.
Intro adapted from Wikipedia (CC BY-SA).
Wadsleyite is an IMA-recognized mineral species in the silicate class, with the chemical formula Mg₂SiO₄.
It crystallizes in the orthorhombic crystal system (space group I2/m). It is a member of the Wadsleyite structural group.
Key properties: specific gravity 3.84; refractive index 1.76; optically biaxial.
IMA symbol Wds, IMA status: approved, named in 1982.
Found in fragments within a vein in a \hypersthene"-olivine chondritic meteorite, believed to have developed during an extraterrestrial shock event.
It is found associated with Ma jorite, ringwoodite, olivine, orthopyroxene, plagioclase, Fe{Ni alloys, troilite.
The name refers to Dr. A.D. Wadsley.