edingtonite

{{Short description|Zeolite mineral}}

{{Infobox mineral

| name = Edingtonite

| image = Edingtonite-120476.jpg

| imagesize = 260px

| alt =

| caption = Edingtonite from Ice River Alkaline Complex, Golden Mining Division, British Columbia, Canada

| category = Tectosilicate minerals, zeolite group

| formula = BaAl₂Si₃O₁₀·4H₂O

| IMAsymbol = Edi{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3 |pages=291–320|doi=10.1180/mgm.2021.43 |bibcode=2021MinM...85..291W |s2cid=235729616 |doi-access=free}}

| strunz = 9.GA.15

| symmetry =

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| color = White, gray, pink

| colour =

| habit = Prismatic pseudotetragonal crystals; massive.

| system = Orthorhombic

| twinning = On [110] and [001]

| cleavage = Perfect on [110]

| fracture =

| tenacity =

| mohs = 4 - 4.5

| luster =

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| diaphaneity =

| gravity = 2.73 - 2.78

| density =

| polish =

| opticalprop = Biaxial (-)

| refractive = n_α = 1.538 n_β = 1.549 n_γ = 1.554

| birefringence = δ = 0.016

| pleochroism =

| 2V = 54 - 62°

| dispersion = r < v; strong

| extinction =

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| other = Pyroelectric and piezoelectric

| prop1 =

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| references = [http://www.webmineral.com/data/Edingtonite.shtml Edingtonite mineral data from Webmineral][http://www.mindat.org/min-1353.html Edingtonite mineral data] from Mindat.org

}}

Edingtonite is a white, gray, brown, colorless, pink or yellow zeolite mineral. Its chemical formula is BaAl₂Si₃O₁₀·4H₂O. It has varieties with tetragonal, orthorhombic or triclinic crystals.Richard V. Gaines, H. Catherine W. Skinner, Eugene E. Foord, Brian Mason, and Abraham Rosenzweig: "Dana's new mineralogy", pp. 1683-1684. John Wiley & Sons, 1997

The mineral occurs within cavities in nepheline syenites, carbonatites, in

hydrothermal veins and various mafic rocks. It occurs associated with thomsonite, analcime, natrolite, harmotome, brewsterite, prehnite and calcite.

The mineral was first reported by and named for Scottish mineral collector James Edington (1787–1844).{{Cite web |url=http://www.handbookofmineralogy.com/pdfs/edingtonite.pdf |title=Handbook of Mineralogy |access-date=2019-05-08 |archive-date=2019-05-08 |archive-url=https://web.archive.org/web/20190508113852/http://www.handbookofmineralogy.com/pdfs/edingtonite.pdf |url-status=dead }} Other sources (including the mineralogist Haidinger) credit Scottish geologist and mineralogist Thomas Edington (1814-1859).{{cite book|title=Biographical Index of Former Fellows of the Royal Society of Edinburgh 1783–2002|date=July 2006|publisher=The Royal Society of Edinburgh|isbn=0-902-198-84-X|url=https://www.royalsoced.org.uk/cms/files/fellows/biographical_index/fells_indexp1.pdf|access-date=2016-04-04|archive-date=2013-01-24|archive-url=https://web.archive.org/web/20130124115814/http://www.royalsoced.org.uk/cms/files/fellows/biographical_index/fells_indexp1.pdf|url-status=dead}} However, as the mineral was named in 1825, the former accreditation must be the true one.Wilhelm Karl von Haidinger, "Description of Edingtonite, a New Mineral Species", in The Edinburgh Journal of Science, V. iii, October 1825, [https://books.google.com/books?id=2SAAAAAAMAAJ&pg=PA316 pp. 316–320]