# Junitoite > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Junitoite > Markdown URL: https://mediated.wiki/source/Junitoite.md > Source: https://en.wikipedia.org/wiki/Junitoite > Source revision: 1312708172 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Sorosilicate mineral}} {{Infobox mineral | name = Junitoite | category = [Sorosilicate](/source/Sorosilicate) | image = File:Junitoite-744478.jpg | imagesize = 260px | caption = Vitreous to pearly junitoite crystals to 4 mm from the Christmas Mine in Gila County, Arizona | formula = CaZn2Si2O7·H2O | IMAsymbol = Jit{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|url=https://www.cambridge.org/core/journals/mineralogical-magazine/article/imacnmnc-approved-mineral-symbols/62311F45ED37831D78603C6E6B25EE0A|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|url-access=subscription}} | molweight = | strunz = 9.BD.15 | dana = 56.2.1.1 | system = [Orthorhombic](/source/Orthorhombic) | class = Pyramidal (mm2)
[H-M group](/source/H-M_group): (mm2) | symmetry = ''A''ma2 | unit cell = a = 12.510(7)
b = 6.318(3)
c = 8.561(6) [Å]; Z = 4 | color = Colorless, milk-white, or colored due to alteration | habit = | twinning = | cleavage = Good on {100}; poor on {010} and {011} | fracture = [Micaceous](/source/Micaceous) | tenacity = Brittle to semi-[sectile](/source/sectile) due to alteration | mohs = 4.5 | luster = Adamantine, Vitreous, Sub-Vitreous | polish = | refractive = nα = 1.656
nβ = 1.664
nγ = 1.672 | opticalprop = Biaxial (+) | birefringence = δ = 0.016 | 2V = Measured: 86°, Calculated: 88° | dispersion = | pleochroism = | fluorescence= | absorption = | streak = Colorless | gravity = | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent to translucent | other = | references ={{cite web|title=Junitoite|url=http://www.mindat.org/min-2123.html|publisher=Mindat|access-date=December 2, 2012}} }} '''Junitoite''' is a mineral with formula CaZn2Si2O7·H2O. It was discovered at the Christmas mine in [Christmas, Arizona](/source/Christmas%2C_Arizona), and described in 1976. The mineral is named for mineral chemist [Jun Ito](/source/Jun_Ito) (1926–1978). ==Description and occurrence== Junitoite is transparent to translucent and is colorless, milk-white, or colored due to alteration. Crystals grow up to {{convert|5|mm|in}} and have high quality faces. Junitoite occurs in fractures through pods of [sphalerite](/source/sphalerite). It formed by [retrograde metamorphism](/source/retrograde_metamorphism) and oxidation of [tactite](/source/skarn), also resulting in kinoite.{{sfn|Williams|1976|p=1255}}{{sfn|Hamilton|Finney|1985|p=91}} The mineral is known from New Jersey and the [type locality](/source/type_locality_(geology)) in Arizona. Junitoite occurs in association with [apophyllite](/source/apophyllite), [calcite](/source/calcite), [kinoite](/source/kinoite), [smectite](/source/smectite), and [xonotlite](/source/xonotlite).{{cite encyclopedia|url=http://www.handbookofmineralogy.org/pdfs/junitoite.pdf |title=Junitoite |encyclopedia=Handbook of Mineralogy |editor1-first=John W. |editor1-last=Anthony|editor2-first=Richard A. |editor2-last=Bideaux|editor3-first=Kenneth W. |editor3-last=Bladh|editor4-first= Monte C. |editor4-last=Nichols |publisher=Mineralogical Society of America|location=Chantilly, VA}} ==Crystal structure== left|thumb|Crystal structure of junitoite. Gray – Ca, green – Ow5, blue – H, yellow – ZnO4, purple – SiO4 In 1968, Jun Ito published the results of synthesis of various lead calcium zinc silicates. The formula of one phase, designated ''X3'', was identified as probably CaZnSi2O6·H2O.{{cite journal|last=Ito|first=Jun|title=Synthesis of some lead calcium zinc silicates|journal=American Mineralogist|date=January–February 1968|volume=53|issue=1–2|url=http://www.minsocam.org/ammin/am53/am53_231.pdf|page=231}} When he described junitoite, Sidney Williams identified the mineral's formula as CaZn2Si2O7·H2O, based on communications with Ito.{{sfn|Williams|1976|p=1255}}{{sfn|Williams|1976|p=1258}} The mineral's [crystal structure](/source/crystal_structure) was first determined in 1985 and refined in 2012.{{sfn|Hamilton|Finney|1985|p=91}}{{sfn|Yang|Jenkins|Downs|2012|p=i73}} The mineral crystallizes in the [orthorhombic crystal system](/source/orthorhombic_crystal_system). The structure is formed by chains of corner-sharing ZnO4 tetrahedra linked together by Si2O7 tetrahedral pairs. Calcium ions occupy vacancies and coordinate to five oxygen atoms and one water molecule.{{sfn|Yang|Jenkins|Downs|2012|p=sup-1}} ==History== The first known specimen of junitoite was collected from the Christmas mine at [Christmas, Arizona](/source/Christmas%2C_Arizona), and entered the collection of Joe Ana Ruiz. Geologist Robert A. Jenkins noticed the mineral in [kinoite](/source/kinoite) specimens, submitting Ruiz's sample to Sidney A. Williams for study. Further samples came from the collections of Ruiz and Raymond Diaz.{{sfn|Williams|1976|p=1255}} Williams identified the specimens as a new mineral and described it in the journal ''American Mineralogist'' in 1976. He named it ''junitoite'' in honor of Jun Ito, the mineral chemist who noted the compound of which the mineral is composed.{{sfn|Williams|1976|p=1258}} The [International Mineralogical Association](/source/International_Mineralogical_Association) approved the mineral as IMA 1975-042.{{cite web|title=The New IMA List of Minerals – A Work in Progress – Update: November 2012|url=http://pubsites.uws.edu.au/ima-cnmnc/IMA_Master_List_(2012-11).pdf|work=Commission on New Minerals, Nomenclature and Classification|publisher=International Mineralogical Association|access-date=December 18, 2012|page=83}} The [type material](/source/type_specimen_(mineralogy)) is housed in the [University of Arizona](/source/University_of_Arizona), [Harvard University](/source/Harvard_University), the [National Museum of Natural History](/source/National_Museum_of_Natural_History), the [University of Paris](/source/University_of_Paris), the [National School of Mines](/source/Mines_ParisTech), and [The Natural History Museum](/source/Natural_History_Museum%2C_London). ==References== {{Reflist|30em}} ;Bibliography *{{cite journal|last1=Hamilton|first1=R. D.|last2=Finney|first2=J. J.|title=The structure of junitoite, CaZn2Si2O7·H2O|journal=Mineralogical Magazine|date=March 1985|volume=49|issue=350|pages=91–95|url=http://www.minersoc.org/pages/Archive-MM/Volume_49/49-350-91.pdf|doi=10.1180/minmag.1985.049.350.13|bibcode=1985MinM...49...91H|s2cid=140636176 }} *{{cite journal|last=Williams|first=Sidney A.|title=Junitoite, a new hydrated calcium zinc silicate from Christmas, Arizona|journal=American Mineralogist|date=November–December 1976|volume=61|issue=11–12|pages=1255–1258|url=http://www.minsocam.org/ammin/AM61/AM61_1255.pdf}} *{{cite journal|last1=Yang|first1=Hexiong|last2=Jenkins|first2=Neil G.|last3=Downs |first3=Robert T.|title=Redetermination of junitoite, CaZn2Si2O7·H2O|journal=Acta Crystallographica Section E|year=2012|volume=E68|issue=10|url=http://rruff.info/uploads/ACE68_i73.pdf|doi=10.1107/S1600536812037622|pmc=3470120|pmid=23125564|page=i73}} ==External links== {{commons category|Junitoite}} *[http://www.mindat.org/gallery.php?min=2123 Images of junitoite] from mindat.org Category:Calcium minerals Category:Zinc minerals Category:Hydrates Category:Sorosilicates Category:Orthorhombic minerals Category:Minerals in space group 40 Category:Minerals described in 1976 --- Adapted from the Wikipedia article [Junitoite](https://en.wikipedia.org/wiki/Junitoite) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Junitoite?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.