Abenakiite-(Ce) is a

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ( ...

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable iso ...

cerium Cerium is a chemical element with the symbol Ce and atomic number 58. Cerium is a soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it often shows the +3 o ...

neodymium Neodymium is a chemical element with the symbol Nd and atomic number 60. It is the fourth member of the lanthanide series and is considered to be one of the rare-earth metals. It is a hard, slightly malleable, silvery metal that quickly tarnishes i ...

lanthanum Lanthanum is a chemical element with the symbol La and atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air. It is the eponym of the lanthanide series, a group of 15 similar elements between lantha ...

, praseodymium,

thorium Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high me ...

, samarium,

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

, and

silicon Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic tab ...

with a

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...

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 The Abenaki (Abenaki: ''Wαpánahki'') are an Indigenous peoples of the Northeastern Woodlands of Canada and the United States. They are an Algonquian-speaking people and part of the Wabanaki Confederacy. The Eastern Abenaki language was predom ...

, an Algonquian Indian tribe of

New England New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York to the west and by the Canadian provinces ...

. Its

Mohs scale The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by th ...

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 Sodalite ( ) is a tectosilicate mineral with the formula , with royal blue varieties widely used as an wikt:ornamental, ornamental gemstone. Although massive sodalite samples are opaque, crystals are usually transparent to translucent. Sodalite i ...

syenite Syenite is a coarse-grained intrusive igneous rock with a general composition similar to that of granite, but deficient in quartz, which, if present at all, occurs in relatively small concentrations (< 5%). Some syenites contain larger proport ...

xenolith A xenolith ("foreign rock") is a rock fragment (country rock) that becomes enveloped in a larger rock during the latter's development and solidification. In geology, the term ''xenolith'' is almost exclusively used to describe inclusions in igne ...

at Mont Saint-Hilaire, Québec, Canada, together with aegirine, eudialyte, manganoneptunite,

polylithionite Lepidolite is a lilac-gray or rose-colored member of the mica group of minerals with chemical formula . It is the most abundant lithium-bearing mineral and is a secondary source of this metal. It is the major source of the alkali metal rubidium. ...

serandite Serandite is a mineral with formula Na(Mn2+,Ca)2Si3O8(OH). The mineral was discovered in Guinea in 1931 and named for J. M. Sérand. Serandite is generally red, brown, black or colorless. The correct name lacks an accent. Description Serandite i ...

, 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
/ref> The hyper-sodium abenakiite-(Ce) is also unique in supposed presence of

sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic activ ...

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 The rare-earth elements (REE), also called the rare-earth metals or (in context) rare-earth oxides or sometimes the lanthanides (yttrium and scandium are usually included as rare earths), are a set of 17 nearly-indistinguishable lustrous silve ...

) * CO₃ groups, NaO₆ octahedra, and disordered SO₂ ligands within the columns

References

External links

*
Mindat.orgWebmineral.org
Sodium minerals Cerium minerals Silicate minerals Phosphate minerals Carbonate minerals Trigonal minerals Minerals in space group 148 Minerals described in 1991 {{silicate-mineral-stub