Chopinite
Chopinite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Mg₃(PO₄)₂.
It crystallizes in the monoclinic crystal system (space group P2_1/b). It is a member of the Olivine-Sarcopside structural group.
Key properties: specific gravity 3.34; optically biaxial.
IMA symbol Cpn, IMA status: approved, named in 2006.
Found in a granulite facies paragneiss (East Antarctica). In a transitional acapulcoite meteorite affected by shock metamorphism.
It is found associated with Fluorapatite, quartz, wagnerite-Ma5bc, xenotime-(Y), stornesite-(Y), P-bearing K-feldspar and plagioclase, Ti-rich biotite, sillimanite, orthopyroxene.
The mineral was named to honor Christian Chopin (b. 1955) of the Ecole Normale Supérieure, Paris, France, for his contributions to the mineralogy of phosphates.