{{Short description|Phyllosilicate mineral}} {{Infobox mineral | name = Chapmanite | category = Phyllosilicate minerals | image = Chapmanite.jpg | caption = Yellow-green earthy massive chapmanite | formula = Fe<sub>2</sub>Sb(SiO<sub>4</sub>)<sub>2</sub>(OH) | IMAsymbol = Cpm<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 = 9.ED.25 | system = Monoclinic | class = Domatic (m) <br/><small>(same H-M symbol)</small> | symmetry = ''Cm'' | color = Yellow, green, olive green | habit = Earthy massive; granular | twinning = | cleavage = Poor | fracture = Conchoidal to irregular | mohs = 2.5 | luster = Nonmetallic, dull to adamantine | refractive = nα=1.850 nβ=1.950 nγ=1.960 | opticalprop = | birefringence = | pleochroism = None | streak = Yellowish green | gravity = 3.69-3.75 | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = | other = }}
'''Chapmanite''' is a rare silicate mineral belonging to the phyllosilicate group, discovered in 1924, and named in honour of the late Edward John Chapman (1821–1904), a geology professor at the University of Toronto. Chemically, it is an iron antimony silicate, closely related to bismutoferrite, and may contain aluminium impurities. It is closely associated with silver mines, most notably the Keeley mine in Ontario, Canada, found in quartz veinlets containing graphite in gneiss. It takes the form of a powdery, yellow-green, semitransparent solid, and leaves a streak of the same color. Early German texts have referred to the mineral as antimon-hypochlorite.
It was recently rediscovered in the southern hemisphere at the abandoned Argent lead mine in Bushveld series rocks of South Africa.
==References== {{Reflist}} *[https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Chapmanite Mineralienatlas] *[http://www.mindat.org/min-970.html Mindat with location data] *[http://www.webmineral.com/data/Chapmanite.shtml Webmineral data] *[https://web.archive.org/web/20051125212814/http://www.minsocam.org/msa/Handbook/Chapmanite.PDF Handbook of Mineralogy] (PDF) * [http://serials.cib.unibo.it/cgi-ser/start/it/spogli/df-s.tcl?prog_art=2547164&language=ITALIANO&view=articoli South African discovery Neues Jahrbuch fur Mineralogie-Monatshefte 2000 #2 pages: 85 - 90]
Category:Antimony minerals Category:Iron minerals Category:Phyllosilicates Category:Monoclinic minerals Category:Minerals in space group 8 Category:Minerals described in 1924
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