A rare mineral consisting of hydrated sodium iron(iii) sulphate, usually occurring as aggregates of greenish- or purplish-white fibrous crystals. Formerly called ferronatrite.
Chemical formula: Na₃Fe(SO₄)₃·3H₂O. Crystal system: trigonal.
Early 20th century; earliest use found in Journal of the Chemical Society. From ferri- + -natrite, after German Ferrinatrit.