Locality: Poudrette quarry (Demix quarry; Uni-Mix quarry; Desourdy quarry; Carrière Mont Saint-Hilaire), Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada FOV 1.3 x 1.5 mm. Via Monteregian Minerals (LH). Stereo pair. MOB coll. The pale yellowish triangular xl in the center is daqingshanite. (It is actually a trigonal pyramid that looks like a shallow tetrahedron.) The xl is less than 0.4 mm on edge. Daqingshanite is a very rare mineral. According to Horvath (Min Rec 1990), it was probably found only once at MSH. I used stereo because the xls are very pale and on a very pale background. Stereo overcomes the lack of contrast to some extent. There are two other daqingshanite xls in the photo but they are even smaller and very hard to spot due to their size and orientation. Again - stereo helps. — Photo: Modris Baum · CC0
Daqingshanite-(Ce)
Daqingshanite-(Ce) is an IMA-recognized mineral species in the phosphate class, with the chemical formula Sr₃Ce(PO₄)(CO₃)₃.
It crystallizes in the hexagonal crystal system (space group R3m).
Key properties: specific gravity 3.81; White streak; Vitreous to greasy luster; optically uniaxial.
IMA symbol Daq-Ce, IMA status: approved, named in 1981.
Found in rare-earth-bearing carbonatite-derived biotite dolomite at the footwall of an iron orebody (Bayan Obo deposit, China); in an intrusive alkalic gabbro-syenite complex (Mont Saint-Hilaire, Canada).
It is found associated with Benstonite, huntite, strontianite, pyrite, phlogopite, monazite (Bayan Obo deposit, China); albite, ancylite, pyrite, anatase, chlorite (Mont Saint-Hilaire.
The name refers to Mt. Daqingshan, near the Bayan Obo deposit, China.