Pyrophanite (FOV 3.5 x 2.5 mm) Locality: Poudrette quarry (Demix quarry; Uni-Mix quarry; Desourdy quarry; Carrière Mont Saint-Hilaire), Mont Saint-Hilaire, Rouville RCM, Montérégie, Québec, Canada Via Jean-Pierre Beckerich. MOB coll. See File:Pyrophanite-183961.jpg for an attempt to show how spectacular the color of pyrophanite can be when brightly lit. — Photo: Modris Baum · Public domain
Pyrophanite
A manganese-titanium oxide of the ilmenite group — deep-red to greenish-black trigonal crystals.
Intro adapted from Wikipedia (CC BY-SA).
Pyrophanite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Mn²⁺TiO₃.
It crystallizes in the hexagonal crystal system (space group R-3). It is a member of the Corundum structural group.
Key properties: Mohs hardness 5–6; specific gravity 4.537; Ocher-yellow, with greenish tinge streak; Metallic to submetallic luster; refractive index 2.349; optically uniaxial.
IMA symbol Pph, grandfathered status — known before the IMA’s founding, named in 1890.
Principally in metamorphosed manganese deposits; less commonly as an accessory mineral in granite, amphibolite, serpentinite; a very rare component in chondritic meteorites.
It is found associated with Ilmenite, geikielite, hematite, spinel, gahnite, chromite, magnetite, ganophyllite, manganophyllite, hendricksite, garnet, calcite.
Its name comes from the Greek for fire and to appear, in allusion to its red color.