Protoenstatite
Protoenstatite is an IMA-recognized mineral species in the silicate class, with the chemical formula Mg₂Si₂O₆.
It crystallizes in the orthorhombic crystal system (space group Pbcn). It is a member of the Pyroxene structural group.
Key properties: specific gravity 3.3.
IMA symbol Pten, IMA status: approved, named in 2016.
Occurs as nano-inclusions in gem-quality “watermelon” labradorite “sunstones” (Oregon).
It is found associated with Labradorite plagioclase, copper, clinoenstatite.
Alludes to a precursor relationship with enstatite and clinoenstatite.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
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