Abenakiite-(Ce) (IMA symbol Abk-Ce) is a mineral of sodium, cerium, neodymium, lanthanum, praseodymium, thorium, samarium, oxygen, sulfur, carbon, phosphorus, and silicon with a chemical formula Na26Ce6(SiO3)6(PO4)6(CO3)6(S4+O2)O.
The silicate groups may be given as the cyclic Si6O18 grouping.
The mineral is named after the Abenaki, an Algonquian Indian tribe of New England.
Its Mohs scale rating is 4 to 5.McDonald, A.M., Chao, G.Y., and Grice, J.D., 1994.
Abenakiite-(Ce), a new silicophosphate carbonate mineral from Mont Saint-Hilaire, Quebec: Description and structure determination.
The Canadian Mineralogist 32, 843-854 Occurrence and association
Abenakiite-(Ce) was discovered in a sodalite syenite xenolith at Mont Saint-Hilaire, Québec, Canada, together with aegirine, eudialyte, manganoneptunite, polylithionite, serandite, and steenstrupine-(Ce).
Notes on chemistry and relation to other species
Combination of elements in abenakiite-(Ce) is unique.
Somewhat chemically similar mineral is steenstrupine-(Ce).Mindat, Abenakiite-(Ce), Mindat.org The hyper-sodium abenakiite-(Ce) is also unique in supposed presence of sulfur dioxide ligand.
With a single grain (originally) found, abenakiite-(Ce) is extremely rare.
Crystal structure
In the crystal structure, described as a hexagonal net, of abenakiite-(Ce) there are:
chains of NaO7 polyhedra, connected with PO4 groups
columns with six-membered rings of NaO7, and NaO7-REEO6, and SiO4 polyhedra (REE - rare earth elements)
CO3 groups, NaO6 octahedra, and disordered SO2 ligands within the columns
References
External links
Mindat.org
Webmineral.org
