Chladniite
Chladniite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Na₃CaMg₁₁(PO₄)₉.
It crystallizes in the hexagonal crystal system (space group R-3). It is a member of the Fillowite structural group.
Key properties: Mohs hardness 4.5–5; specific gravity 3.01; Vitreous to resinous luster.
IMA symbol Clad, IMA status: approved, named in 1993.
Found as a single grain in a phosphate-rich inclusion in an iron meteorite (Carleton meteorite); in phosphate-rich portions of an acapulcoite-lodranite meteorite.
It is found associated with Chlorapatite, olivine, pyroxene, plagioclase, schreibersite, nickel-iron, troilite, kamacite.
The mineral was named to honor Professor Ernst Florens Friedrich Chladni (1756–1827), German physicist, University of Riga, Riga, Latvia.