What is Xenophyllite?
Xenophyllite is a rare sodium iron phosphate first recognised in meteorites, where dark grains record shock and unusual phosphate chemistry.
Mineralogy and structure
Reference formula: Na4Fe2+7(PO4)6. Xenophyllite is triclinic and its natural chemistry can include potassium, manganese and chromium substitutions. COD 2238680 is used as an exact structural reference for a published xenophyllite composition. Xenophyllite is classified with phosphates and has triclinic crystal symmetry. Typical hardness is 3.5–4 on the Mohs scale and specific gravity is approximately 3.5–3.7.
Colour, lustre and habit
Typical colours include dark green, greenish black, brown-black, black. The usual platy, granular, massive habit and vitreous, pearly, dull lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Xenophyllite forms in or is associated with meteorites, shock-modified phosphate assemblages and reducing extraterrestrial environments. Important documented localities include Augustinovka and other Ukrainian meteorites, Muonionalusta-related material and specialist meteorite collections.
A meteorite phosphate with battery-relevant chemistry
Xenophyllite connects meteoritics, crystal chemistry and materials science. Its sodium mobility and channel-like phosphate structure make an authenticated grain far more interesting than its dark colour suggests.
Collecting and care
Protect small grains from abrasion and contamination; retain meteorite provenance and do not cut or grind without professional controls.
