Adamite

{{Short description|Zinc arsenate hydroxide mineral}} {{about|the mineral|the religious sect|Adamites}} {{Infobox mineral | name = Adamite | category = Arsenate mineral | boxwidth = | boxbgcolor =#70883a | boxtextcolor = #fff | image = Adamite-179841.jpg | caption = Yellow-green adamite in limonite | formula = Zn₂AsO₄OH |IMAsymbol=Ad<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> | molweight = | strunz = 8.BB.30 | dana = 41.06.06.03 <br/>Olivenite group | system = Orthorhombic | class = Dipyramidal (mmm) <br/>H–M symbol: (2/m 2/m 2/m) | symmetry = ''Pnnm'' | color = Pale yellow, honey-yellow, brownish yellow, reddish; rarely white, colorless, blue, pale green to green, may be zoned | habit = Wedge-like prisms typically in druses and radiating clusters; also smooth botryoidal masses | twinning = | cleavage = {101}, good; {010}, poor | fracture = Uneven to subconchoidal | tenacity = Brittle | mohs = 3.5 | luster = Vitreous | refractive = n_α=1.708 – 1.722, n_β=1.742 – 1.744, n_γ=1.763 – 1.773 | opticalprop = Biaxial (+/−) | birefringence = δ = 0.055 | pleochroism = | streak = White to pale green | gravity = 4.32–4.48 measured | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = | other = May fluoresce and phosphoresce lemon-yellow under SW and LW UV. | references = <ref name=Handbook>http://rruff.geo.arizona.edu/doclib/hom/adamite.pdf Handbook of Mineralogy</ref><ref name=Mindat>http://www.mindat.org/min-21.html Mindat.org</ref><ref name=Webmin>http://webmineral.com/data/Adamite.shtml Webmineral data</ref> }}

'''Adamite''' is a zinc arsenate hydroxide mineral, Zn₂AsO₄OH. It is a mineral that typically occurs in the oxidized or weathered zone above zinc ore occurrences. Pure adamite is colorless, but usually it possess yellow color due to Fe compounds admixture. Tints of green also occur and are connected with copper substitutions in the mineral structure. Olivenite is a copper arsenate that is isostructural with adamite and there is considerable substitution between zinc and copper resulting in an intermediate called ''cuproadamite''. Zincolivenite is an intermediate mineral with formula CuZn(AsO₄)(OH). Manganese, cobalt, and nickel also substitute in the structure. Tarbuttite is an analogous zinc phosphate. [[File:Adamite - Gild Hill, Deep Creek Mountains, Tooele County, Utah, USA.jpg|thumb|left|Adamite on limonite from the Gold Hill District Tooele County, Utah, US. Scale at bottom is {{circa}} 2.5 cm.]]

==Occurrence== Adamite occurs as a secondary mineral in the oxidized zone of zinc- and arsenic-bearing hydrothermal mineral deposits. It occurs in association with smithsonite, hemimorphite, scorodite, olivenite, calcite, quartz and iron and manganese oxides.<ref name=Handbook/>

The yellow to bright lime-green colored crystals and druze along with its distinctive fluorescence make adamite a favorite among mineral collectors. Found in Mapimí, Durango, Mexico; Greece; and California and Utah in the United States.

Adamite was named after the French mineralogist Gilbert-Joseph Adam (1795–1881). It was first described in 1866 for an occurrence at the type locality of Chañarcillo, Copiapó Province, Atacama Region, Chile.<ref name=Mindat/>

==See also== * List of minerals * List of minerals recognized by the International Mineralogical Association * List of minerals named after people

==References== {{Reflist}}

{{commons}} {{Americana Poster|year=1920}}

Category:Zinc minerals Category:Arsenate minerals Category:Hydroxide minerals Category:Orthorhombic minerals Category:Minerals in space group 58 Category:Luminescent minerals Category:Minerals described in 1866