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 2.3 x 2.9 mm. Found Sept 1994. MOB coll. Resinous brown synchysite-(Ce). — Photo: Modris Baum · CC0
Synchysite-(Ce)
Synchysite-(Ce) is a carbonate mineral and an end member of the synchysite group. The general chemical formula is Ca(Ce,La)(CO3)2F.
Intro adapted from Wikipedia (CC BY-SA).
Synchysite-(Ce) is an IMA-recognized mineral species in the carbonate class, with the chemical formula CaCe(CO₃)₂F.
It crystallizes in the monoclinic crystal system (space group C2/c).
Key properties: Mohs hardness 4.5; specific gravity 3.9; Vitreous to subadamantine, may be greasy luster; optically uniaxial.
IMA symbol Syn-Ce, IMA status: approved, named in 1901.
An uncommon hydrothermal accessory mineral in granites and alkalic syenites.
It is found associated with Astrophyllite, catapleiite, neptunite, epididymite, elpidite, cordylite, fluorite, rhodochrosite, polylithionite, aegirine, microcline, albite (Narssârssuk.
Its name comes from the Greek for confounding, as originally thought to be parisite, and dominant cerium.