# Copiapite > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Copiapite > Markdown URL: https://mediated.wiki/source/Copiapite.md > Source: https://en.wikipedia.org/wiki/Copiapite > Source revision: 1334885243 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Hydrated iron sulfate mineral}} {{Infobox mineral | name = Copiapite | category = [Sulfate minerals](/source/Sulfate_minerals) | image = Copiapite-159310.jpg | caption = Copiapite from the Bolesław Mine, Kłodzko District, [Lower Silesia](/source/Lower_Silesia), [Poland](/source/Poland) | formula = Fe2+Fe3+4(SO4)6(OH)2·20(H2O) | IMAsymbol = Cpi{{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}} | molweight = | strunz = 7.DB.35 | dana = | system = [Triclinic](/source/Triclinic) | class = Pinacoidal ({{overline|1}})
(same [H-M symbol](/source/H-M_symbol)) | symmetry = ''P''{{overline|1}} | unit cell = a = 7.337 Å, b = 18.76 Å,
c = 7.379 Å; α = 91.47°,
β = 102.18°, γ = 98.95°; Z = 1 | color = Sulfur-yellow to orange when crystalline, greenish-yellow to olive-green when massive | colour = | habit = Tabular pseudo-orthorhombic platy crystals, typically in scaly incrustations or granular pulverulent aggregates | twinning = Contact twins | cleavage = Perfect on {{mset|010}}, imperfect on {{mset|{{overline|1}}01}} | fracture = Irregular/uneven, micaceous | tenacity = Fragile | mohs = 2.5–3 | luster = Pearly on {010} | streak = | diaphaneity = Transparent to translucent | gravity = 2.04–2.17 | density = | polish = | opticalprop = Biaxial (+) | refractive = nα = 1.506 – 1.540 nβ = 1.528 – 1.549 nγ = 1.575 – 1.600 | birefringence = δ = 0.069 | pleochroism = X = Y = pale yellow to colorless; Z = sulfur-yellow | 2V = Measured: 45° to 74°, Calculated: 48° to 72° | dispersion = | extinction = | length fast/slow = | fluorescence= | absorption = | melt = | fusibility = | diagnostic = | solubility = Soluble in water | other = | alteration = | references = [https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Copiapite Mineralienatlas][https://rruff.geo.arizona.edu/doclib/hom/copiapite.pdf Handbook of Mineralogy][http://www.pnas.org/content/96/7/3455.full (Nordstrom and Alpers, 1999)][http://www.mindat.org/min-1124.html Mindat.org] }} '''Copiapite''' is a hydrated [iron](/source/iron) [sulfate](/source/sulfate) mineral with formula: Fe2+Fe3+4(SO4)6(OH)2·20(H2O). Copiapite can also refer to a mineral group, the copiapite group. Copiapite is strictly a secondary mineral forming from the [weathering](/source/weathering) or [oxidation](/source/oxidation) of [iron](/source/iron) [sulfide mineral](/source/sulfide_mineral)s or sulfide-rich coal. Its most common occurrence is as the end member mineral from the rapid oxidation of [pyrite](/source/pyrite). It also occurs rarely with [fumarole](/source/fumarole)s. It occurs with [melanterite](/source/melanterite), [alunogen](/source/alunogen), [fibroferrite](/source/fibroferrite), [halotrichite](/source/halotrichite), [botryogen](/source/botryogen), [butlerite](/source/butlerite) and [amarantite](/source/amarantite). It is by far the most common mineral in the copiapite group. It rarely occurs as single crystals, is in the [triclinic](/source/triclinic) crystal system, and is pale to bright yellow. It is soluble in water, changing the water color to deep orange or orangish-red. In solution copiapite is very acidic. In high concentrations a negative pH can occur, as reported in waters draining from [Richmond Mine at Iron Mountain](/source/Iron_Mountain_Mine), California. Copiapite can easily be distinguished from native [sulfur](/source/sulfur) because it does not give off an odor when dissolved in water. It can be distinguished from similar appearing [uranium](/source/uranium) minerals, such as [carnotite](/source/carnotite), by its lack of radioactivity. The only way to differentiate between the minerals in the copiapite group is by [X-ray diffraction](/source/x-ray_crystallography). Copiapite was first described in 1833 for an occurrence near [Copiapó](/source/Copiap%C3%B3), [Atacama](/source/Atacama_Region), [Chile](/source/Chile). It is sometimes known as ''yellow copperas''. Other occurrences are in California, Nevada, and in the filled paleo sinkholes and caves of Missouri. [[File:Copiapite-199662.jpg|thumb|none|Lustrous, micaceous crystals of copiapite to 8 mm on matrix from the Alcaparrosa Mine, El Loa Province, [Antofagasta Region](/source/Antofagasta_Region), [Chile](/source/Chile) (sample size: 11.9 × 7.4 × 4.0 cm)]] ==See also== {{Portal|Earth sciences}} * [Classification of minerals](/source/Classification_of_minerals_(disambiguation)) * [List of minerals](/source/List_of_minerals) ==References== {{Reflist}} {{Commons category}} Category:Iron(II,III) minerals Category:Sulfate minerals Category:Triclinic minerals Category:Minerals in space group 2 Category:Minerals described in 1833 --- Adapted from the Wikipedia article [Copiapite](https://en.wikipedia.org/wiki/Copiapite) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Copiapite?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.