{{Short description|Iron tellurite mineral}} {{Infobox mineral | name = Emmonsite | image = Emmonsite-mrz266a.jpg | alt = | caption = Emmonsite. Locality: San Miguel Mine, Moctezuma, Sonora, Mexico (size: 6.3 x 4.1 x 1.1&nbsp;cm) | category = Tellurite mineral | formula = Fe<sub>2</sub>(TeO<sub>3</sub>)<sub>3</sub>·2(H<sub>2</sub>O) | IMAsymbol = Ems<ref>{{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}}</ref> | strunz = 4.JM.10 | dana = | system = Triclinic | class = Pinacoidal ({{overline|1}}) <br/><small>(same H-M symbol)</small> | symmetry = ''P''{{overline|1}} | unit cell = a = 7.90, b = 8.00 <br/>c = 7.62&nbsp;[Å]; α = 96.73°<br/>β = 95°, γ = 84.47°; Z&nbsp;=&nbsp;2 | color = Yellowish green | habit = Thin to hairlike crystals, occurring in rosettes and sprays; also fibrous globular aggregates and crusts | twinning = Noted | cleavage = Perfect on {010}; good on {100} and {001} | fracture = | tenacity = | mohs = 5 | luster = Vitreous | streak = | diaphaneity = Opaque to translucent | gravity = 4.52–4.55 | density = | polish = | opticalprop = Biaxial (-) | refractive = n<sub>α</sub> = 1.962 n<sub>β</sub> = 2.090 n<sub>γ</sub> = 2.100 - 2.120 | birefringence = δ = 0.138 - 0.158 | pleochroism = Weak | 2V = Measured: 23° | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | references = <ref name=Handbook>''Mineral Data Publishing'', [http://www.handbookofmineralogy.org/pdfs/emmonsite.pdf Handbook of Mineralogy pdf]</ref><ref name=Mindat>[http://www.mindat.org/min-1377.html Emmonsite on Mindat website]</ref><ref name=Webmin>[http://webmineral.com/data/Emmonsite.shtml Emmonsite data on Webmineral.com]</ref> }}

'''Emmonsite''', also known as '''durdenite''', is an iron tellurite mineral with the formula: Fe<sub>2</sub>(TeO<sub>3</sub>)<sub>3</sub>·2(H<sub>2</sub>O).<ref name=Handbook /> Emmonsite forms triclinic crystals.<ref name=Handbook /> It is of a yellowish-green color, with a vitreous luster,<ref name=Handbook /> and a hardness of 5 on the Moh scale.<ref name=Mindat/> thumb|left|Emmonsite crystal spray from the Moctezuma Mine (3 mm image width) Emmonsite was first described in 1885 for an occurrence in the Tombstone District, Cochise County, Arizona. It was named for the American geologist, Samuel Franklin Emmons, (1841–1911), of the United States Geological Survey.<ref name=Handbook /><ref name=Mindat />

Emmonsite is found, often with quartz or cerussite in the Tombstone, Arizona area.<ref name=Mindat /> It is also associated with native tellurium, tellurite, native gold, pyrite, rodalquilarite, mackayite, sonoraite, cuzticite and eztlite.<ref name=Handbook />

==References== {{commonscat|Emmonsite}}

{{Reflist}} {{Refbegin}} *Frost, Ray L. and Dickfos, Marilla J. and Keeffe, Eloise C. (2008) "Raman spectroscopic study of the tellurite minerals: emmonsite Fe23+Te34+O9.2H2O and zemannite Mg0.5[Zn2+Fe3+(TeO3)3]4.5H2O." ''Journal of Raman Spectroscopy'', 39(12). pp.&nbsp;1784–1788. Found at [https://web.archive.org/web/20120229212408/http://eprints.qut.edu.au/16798/ Queensland University of Technology website]; Accessed September 15, 2010. *W. F. Hillebrand, "Emmonsite (?) from a new locality," American Journal of Science, Series 4 Vol. 18, December 1904, P.433-434; {{doi|10.2475/ajs.s4-18.108.433}}. Found at [http://www.ajsonline.org/cgi/content/abstract/s4-18/108/433 AJS Online]; Accessed September 15, 2010. {{Refend}}

{{Selenites, selenates, tellurites, and tellurates}}

Category:Iron(III) minerals Category:Tellurite minerals Category:Triclinic minerals Category:Minerals in space group 2 {{mineral-stub}}